Boxed items sold by collectors will be expensive, specially if you want a 1992 build with good quality hardware, i guess 1987 games were mostly ega/vga running on a 286 correct so i guess a good chunk of those games wouldn't be speed sensitive, with that in mind i suppose that you can get a 486 DX 33 and with using the turbo button/ cache tricks you would be able to slow it down to games that run way to fast(Wing Commander for example).
My dx4-100 runs Wing Commander a little bit too fast even on slow mode.

About the games, if you don't mind, GOG DOS games are pretty easy to get working on a real dos machine(basically copying the file and maybe burning the image), also there is alot of games that are abandonware and distributed freely, it is just googling around, now if you wanna a boxed copy of the game, give a look on ebay, and local thrift shops, or another marketplaces.
but here we have the complete trilogy of jill for free on GOG https://www.gog.com/game/jill_of_the_jungle_t … omplete_trilogy

VOGONS is not a marketplace, so watch out; you'd better edit your thread or it will be removed.

Ask for advice on where to find what you're looking for. Don't ask directly if anyone here will sell you something.

Like Keenmaster486 say... Not a marketplace. That you must go to eBay, Amibay or some third or fourth source for.

I suggest posting your request on the vintage computer forum. The focus of this forum is not to provide items for sale; there are several other venues for that. Specific links for "computer items wanted""

http://www.vcfed.org/forum/forumdisplay.php?2 … er-Items-Wanted
http://www.cpu-world.com/forum/viewforum.php?f=5
http://www.amibay.com/forumdisplay.php?15-Wanted-Hardware