The alternatives to President Reagan's tax proposal that will be submitted to the House Ways and Means Committee by Chairman Dan Rostenkowski (D-Ill.) today will attempt to shift some of the financial benefits of tax revision away from higher-income taxpayers and "traditional" families, congressional sources said yesterday.

The Rostenkowski options, not the Reagan proposal, will serve on some provisions as the committee's starting point as it begins crafting a plan to reshape the tax code. The options will include possible changes in Reagan's proposal in areas such as capital gains taxation, the standard deduction, write-offs for business investment and the deduction for state and local taxes, sources said.

The White House, meanwhile, insisted that support for tax revision is increasing as Reagan promotes it in his series of trips around the country. White House spokesman Larry Speakes took issue with the conclusions of a Washington Post-ABC News poll that found 22 percent of the respondents in favor of the Reagan tax plan, 22 percent opposed and 56 percent with no opinion. Slightly more people oppose the president's plan now than did in June, just after it was proposed.

Speakes blamed public cynicism principally on the news media.

"There has been a fairly steady drumbeat of skepticism in this press room, and in other press rooms, for two years on the president's tax plan," Speakes said. He added that "built-in bias toward a tax-reform plan is augmented by special-interest groups beating the drums in favor of their various interests."

As Speakes was criticizing news coverage of the tax-overhaul plan, Ways and Means Committee aides yesterday were finishing work on a menu of options that they said are intended to serve as a starting point and are subject to change by the panel. They declined to discuss details.

Ways and Means staff members would not confirm or deny rumors sweeping congressional and lobbying offices that the Rostenkowski plan calls for setting today as the effective date for implementation of any changes in the investment tax credit. That would prevent companies from making investments based on when they think a tax bill might pass.

But some congressional sources offered assessments of what the chairman is likely to propose:

*State and local taxes: The Reagan plan would terminate the deduction for state and local income, sales and property taxes. Rostenkowski, swamped with objections from committee members from such high-tax states as New York and Massachusetts, is expected to propose a compromise that would bring in about half of the additional revenue that eliminating the deduction would collect. Sources say the compromise probably will give taxpayers a choice: They could deduct a flat dollar amount, of perhaps $1,000. Or, they could deduct state and local taxes to the extent they exceed a fixed percentage of income, such as 5 percent. They could take whichever deduction is greater.

*Fringe benefits: Labor unions and others have strongly objected to Reagan's proposal to tax the first $10 per month for individuals and $25 per month for families of health-insurance premiums paid by companies on behalf of their workers. Rostenkowski may propose reversing that approach, taxing only the portion of those premiums that exceeds a fixed dollar amount. That amount is expected to be considerably higher than the level first proposed by the Treasury Department, $70 per month for individuals and $175 a month for families. As a result, the Rostenkowski alternative would involve raising the taxes of few taxpayers.

*Capital gains: The Reagan plan would cut the top tax rate on capital gains -- profits from the sale of an asset -- from the current 20 percent to 17.5 percent. Committee Democrats have complained that this would disproportionately help well-off taxpayers. Rostenkowski is expected to suggest either keeping the top rate 20 percent or raising it a percentage point or two higher.

*Personal exemption and standard deduction: The administration proposal called for doubling the personal exemption, the $1,000 that every taxpayer can take on his tax form for himself and for each dependent. Rostenkowski will propose limiting this increase to lower-income taxpayers in response to objections that the Reagan proposal principally helps "traditional" families with one income earner and multiple children. He probably will suggest altering the thrust of the standard deduction, or zero bracket amount -- the amount taxpayers who do not itemize their deductions can subtract from their incomes before paying taxes -- by varying it according to family size.

*Rates: The committee is expected to begin its work using Reagan's proposed individual tax rates of 15 percent, 25 percent and 35 percent (the current top rate is 50 percent). There also will be no initial change in the proposed cut in the corporate tax rate from 46 percent to 33 percent.

*Business taxes: The administration proposal to eliminate the investment tax credit, which pays for up to 10 percent of the cost of new equipment, will be retained. But its proposed tax increase on companies that have postponed paying taxes through general depreciation write-offs is likely to be modified or eliminated.

A White House official said Reagan will refrain from criticizing the actions of Ways and Means as it works on the bill. "Rosty wants it that way," this official said, emphasizing that the White House is depending on Rostenkowski and the Democrats to get the tax bill through the House.