Quality Inns International yesterday unveiled its "room of the '90s"--an oversize modular motel unit featuring a hot tub for two, in-room computer, stereo, movies, video games and a tax shelter for investors.

What the Silver Spring lodging chain calls the Quality Choice Suite is meant to be built in a factory, trucked to a site and lifted into place with a crane, holding down costs so the room can be rented for $40 a night.

Announcing the venture at a hospitality industry investment conference yesterday in New York, President Robert C. Hazard Jr. said, "There's a wide-open market for a unique, exciting product priced at $40 a night."

Appealing to the business traveler or weekend vacationer, Quality Inns new product is aimed at the same market targeted last week by cross-town rival Marriott Corp., which plans to build five Courtyard Inns to test the demand for moderately priced up-scale lodging.

Although Marriott plans to build and operate its own properties, Quality Inns hopes to lure private investors and franchise operators with a tax-shelter financing plan.

Not only is the modular motel room economical to construct--about $32,500 a room compared with $100,000 for conventional hotel rooms--it potentially can qualify for special tax benefits, Hazard said.

Citing an opinion by Laventhal and Horwath, the accounting firm that specializes in the lodging industry, Hazard said investors who put $1 million into the venture would qualify for $2.5 million in tax deductions.

As much as 90 percent of the construction cost plus all the furnishings and equipment can qualify for investment tax credits. That means, Hazard said, that builders can write off 10 percent of the cost immediately and then depreciate the remainder of the cost over five years instead of the usual 15 years.

Hazard said a prototype of the new room has been built in Denver. It's basically a 14-foot-wide, 29-foot-long modular home unit, about 40 percent larger than the average motel room.

Instead of the usual 5-by-7 foot bathroom, he added, the Quality Suite has a 77-square foot bath that includes "a luxurious 'Happy Tub' for two, done in French vanilla with brass faucets" that "can be entered from either the bathroom or from the living area."

Using the optional whirlpool bath will add $5 to the room rate and a $5 surcharge also is planned for viewing movies on the in-room entertainment center. The TV, he noted, can be viewed from the bed, a sofa or the hot tub.

"Some people say it's too early to talk about a personal computer in every guest room," Hazard said. "Perhaps it's long overdue. Microprocessors are here to stay, and the lodging chain of the 90s will have to offer them for both video games and business applications."