Another poster was right in saying your best bet was to find an old system locally, but it's a tough find for stuff this old. Piecing it together through ebay or online is easy but expensive, shipping kills! You already have a case and PS and that's the biggest hurdle because of weight. Many of these old mobos take AT case's and PS's so check your parts and make sure they're compatible. I have several slot 1 CPU's, a couple socket 7 CPU's, various mobo's, some memory, VLB, PCI, AGP Graphics cards, Soundblaster ISA cards, and ISA modems and NIC cards (just in case you want to Doom deathmatch) I charge $5 a part + actual shipping (Mobo might be more depending on type) If anyone thinks that's too pricey feel free to check ebay, it's usually .01 + $10+ shipping! Forget the Qemm you won't need it. You can edit the config.sys and autoexec.bat to get 617k of base which is enough for every game I've tried. Depending on the mobo you may need a PS/2 to serial adapter for the mouse and a ps/2 to Dinn adapter for the keyboard. And last but not least, if you have any games on 5 1/4" disk, those drives are TOUGH to find in working condition. Hope that helps.
Ultima, Wizardy, System Shock here you come!