We all have different goals but personally from your collection I would probably keep the 233mmx as I really lusted over MMX back in the day when I was still using my dx4(I was using dx4 until 2000s!!). Probably wouldnt get used much tho!
Then probably make the fastest P3 you can with an isa slot for sound and then a voodoo 3.
And one of the shuttles for the XP stuff.
That would nicely cover dos/95 with the mmx. 98 with the p3 and xp with the shuttle!
My machines (currently built. Still have this 2003 build to do...)
Trigem OEM mobo/case with dx2 66 and 32mb ram. SB 2.0. 500mb CF. Dos 6.22/win3.11. This machine is a little special to me as I got it from a terrible state to one that is really usable but the case is a bit beaten up and I have spent out more than I think I could get back on it.
AT desktop case with 3digit speed display. 486 dx4 100 32mb ram. 2gb CF. VLB i/o and vga. Sound galaxy NX pro. Win 95. This machine while a pleasure to build and get running is just awkward. Its interesting but a bit sluggish. I could probably make good money on this one splitting it for parts...
Toshiba satellite 4000CDT. p2 233mhz with 32mb ram. onboard yamaha audio and 2mb chips & tech gpu. Windows 98. This is actually a great little laptop but the cmos battery has gone in it and its a fiddly job to sort. I really should get on it because they can leak.
Compaq deskpro. P2 450mhz with 192mb ram. onboard audio and an odd form factor ati rage turbo 8mb. Windows ME. This is actually a really nice machine to use and is another one I was pleased to restore even if it was only a strip down and clean. it is however HUGE and heavy.
NoS desktop case. P3 @ 950mhz. 512mb ram. 16gb CF. AWE32 and voodoo 3. Windows 98. This machine is my go to rig. Everything about it is great its so compatible and runs flawlessly. If not a little bit loud. It could also be considered that is cost me nothing as every piece was part of a "lot" where the other parts will sell for more than the outlay.
Compaq deskpro. p3 1ghz with 512mb ram. built in audio and TNT2 pro. 1gb HDD. Windows 98. This is a strong machine really and is SFF but no AGP or ISA just make it seem a bit dull. Even if it is perfectly fine without them.
Mesh beige tower case. Athlon 1ghz. 512mb ram. SBLive. GF3 ti 200. 40gb hdd. Windows 98. Perfectly fine machine but ISA is now gone so we are done with DOS and moving forward to XP ERA performance. Does not compete with other systems I have(or will have) for XP so is collecting dust.
very cheap black case. Athlon 1600xp+(I think) 256mb ram. (this board is really fussy with memory) GF4 mx440. Audigy 2. 20gb HDD. Windows XP. Built from random parts. Runs great but quite slow for XP Era systems.
I think I should lose at least the compaqs and the athlons. probably 1 or both 486s too but I am slightly attached to them.