SystemDown:
I think just about any laptop will work for stumbing/surveys. I use a Compaq LTE5300 along with a Proxim Symphony WLAN card(DO NOT USE THESE!) for my micro-net, but I can NOT use ANY Proxim card with NetStumbler, they use the Prism2 chipset and are Home RF, NOT 802.11b compliant, so they will not work with any of the survey software that is curently available. They are also FHSS(Frequency Hopping Spread Spectrum) and not DSSS(Direct Sequence Spread Spectrum) like the Orinoco silver/gold cards, get one of those over ANY Proxim card, unless all you want to do is run a small home network, which is all you'll be able to do with Proxim cards(I didn't RTFM first, so I lost out!).
I know of many Sony VAIOs, Compaqs and IBMs being used, so the list is long, and I'll bet any machine that has Linux, Windows and so on will work without any troubles.

I have noticed many folks run Linux, and Windows, so you should have no problems calling for help should you need it.

I hope this is of use to you, good luck in your endeavors!

73!
DATA, KA9UCE, A.E.C
ka9uce@NOSPAMnetscape.net