[Bored of the Rings]
I sit on the floor and pick my nose
And dream exotic dreams
Of dragons who dress in rubber clothes
And trolls who do it in teams.
[/BotR]
Places like Mr. S Leather sell latex clothes and might also offer the material in sheets.
Probably not cheap, though, by the time they’ve gone off and imported it from the UK (last I knew, that’s where they got it from) then made their typical retail profit on it.
A quick search seems to indicate that surgical gloves go between 5 and 10 mils, typically. Ten mil material would seem to fit the OP’s requirement. But, probably not enough to make very much clothing out of it. Maybe a latex bikini. Hmm…