You can usually compensate for this by running programs specifically designed to slow down your computer. Mo'Slo used to be pretty much the only choice here, but there are other options these days. I haven't tried many of them, so I can't really comment on which ones work best. I do remember having a very difficult time trying to slow down my Pentium 133 enough to play Montezuma's Revenge, which I think was meant to be played on an 4 MHz 8088, as even at 1% speed, it was still too fast.
There are also all kinds of other errors that can crop up on newer computers. Sometimes the errors are also caused by the speed difference, but give you misleading messages that confuse the actual problem. Home of the Underdogs has a FAQ that lists some of them.
A laptop might be your best bet then... but you still have to know IRQ's and IO addresses and stuff, even with a laptop... so it might not help as much as you think it will. Laptops of the time were generally bad for playing games on though... but with a newer machine, you might have trouble getting features to work with DOS (sound and CD-ROM might give you a hard time)... so you might have some trouble finding just the right balance here.I don't know much about installing hardware on old machines though...I was hoping for a sort of "set" where the monitor and drives are all in one--or at least something with some character rather than the normal monitor, computer, keyboard and mouse.
I'd recommend either a 486 or Pentium, somewhere in the 66 MHz to 133 MHz range. Look for something with ISA ports on the motherboard, that way you can be confident of finding DOS and Win 3.1 drivers for pretty much all of the hardware you'd ever put in it. Finding graphics cards, hard drives, CD-ROM drives, and floppy drives should be very easy... but finding just the right sound card might prove tricky. I'd recommend a SoundBlaster-16 to get the best compatibility. It's not the best *sounding* card, but you'll have to jump through a lot less hoops than you would with something like a Roland MT-32, Gravis Ultrasound, or even newer SB cards like the AWE-32.
--Zero