Congressional supporters of Israel warned yesterday that the Reagan administration's plans to sell advanced weaponry to Jordan and Saudi Arabia would provoke "an enormously divisive" arms-sales debate and would result in a "total fiasco" for its efforts to renew simultaneously the peace process.

Speaking hours before a closed-session briefing for three House committees on a new administration study of Middle Eastern countries' arms needs, Rep. Tom Lantos (D-Calif.) and Lawrence J. Smith (D-Fla.) attacked the administration for presenting the document at what Lantos called "the least opportune time."

"You're setting yourself up in a very, very confrontational mode with both the House and Senate," Smith remarked.

Lantos said it "simply boggles the human mind" to expect Israel to engage seriously in "dramatic negotiations" for peace and at the same time to cope with a new American proposal to sell sophisticated arms to its Arab neighbors.

The comments by the two House members, known as strong supporters of Israel, were taken as a precursor of the likely reaction of many senators and representatives who have already backed resolutions or amendments expressing strong opposition to selling new sophisticated arms to Jordan and Saudi Arabia now.

In late afternoon, the classified study was presented to a combined session of the House committees on foreign affairs, appropriations and armed services by William Schneider Jr., undersecretary of state for security assistance, and Lt. Gen. Philip C. Gast, head of the Pentagon's Defense Security Assistance Agency.

The arms-transfer study is expected to be followed, probably in September, by administration requests to sell additional advanced aircraft, mobile ground-to-air and air-to-air missiles to Jordan and Saudi Arabia.

Seeking to allay congressional concern, Assistant Secretary of State Richard W. Murphy told the House Middle East subcommittee yesterday that the study was "not a decision document" and made no specific recommendations for any arms sales. He did say, however, that the study's data would provide "a framework for decisions" on arms sales requests.

Murphy also told the subcommittee that "some" of the seven names of Palestinians being considered for a Jordanian-Palestinian delegation to preliminary talks with the United States were acceptable to Washington. He did not indicate which, but noted that Prime Minister Shimon Peres yesterday reversed his initial opposition to the list and accepted the two West Bank residents on it, Hanna Seniora and Fayez Abu Rahme.

Murphy said no decision had been made on when he would travel to Amman, Jordan, where he is expected to meet with a Jordanian-Palestinian group for preliminary talks. Israel is still strongly opposed to the meeting because it fears the outcome may be the start of a dialogue between the United States and the Palestine Liberation Organization (PLO), which it regards as a terrorist group and has said it will never deal with.

The State Department official said there was no change in Washington's refusal to negotiate with the PLO before the PLO recognizes Israel, but also reaffirmed that it makes a distinction -- unlike Israel -- between members of the PLO and the Palestine National Council, its parliament-in-exile. Non-PLO members in the latter body remained possible candidates for a peace delegation, he said.

Murphy indicated Washington was still assessing whether, and how, the proposed U.S.-Jordanian-Palestinian meeting would lead to direct negotiations with Israel.

"The question is, where does it go?" he said. "That's the question we are putting out to the region. We want it to go toward direct negotiations."

Washington was continuing to consult closely with Israel on the whole process, he said, but would make its own final decision on the "benefit" of such a preliminary meeting even if Tel Aviv continued to oppose it.

Defending the administration's efforts to get Middle East peace negotiations under way again, Murphy said there had been "a sea change" in the Arab attitude toward Israel in the past few years and that, in any case, the timing for "a big push" to renew the process was "not an exclusive American calendar."