I have built a gaming system inside of an Aspire X-Qpack, with the only nforce4 micro-atx motherboard i could find - a Foxconn winfast NF4K8MC.
The 350w Aspire PS is a 24-pin, and it is plenty to support everything i have - a64 4000, 1gb (1 stick) of ram, dvd burner, 1 hdd, x850xtpe... Could potentially support more, but thats all i have to put in it.
And depending on what games you play, an extra gig of ram can make the difference. I play alot of world of warcraft. My old system, an a64 3200 w/ 1.5gb of ram and an x800xl, loaded wow - particularly ironforge - and played noticeably smoother than my new system, with only 1gb of ram and a bit of a better processor and video card. Oh, by the way, that foxconn board does not like Mushkin ram - or else i would have 1.5gb of ram in this system >_<
Feel free to PM me if you have some particular question about it...
*edit* oh, for the record, a Zalman 92mm copper heatsink/fan just barely clears the motherboard tray, but it does fit. I'de reccomend it for your overclocking cooling needs.
and speaking of cooling in the case.. the only reasonably hotspot in the case is in the expansion card area, because the power supply is right above it. The power supply does have a fan that sucks a bit of air from there, but it moves too slowly to do much. If expansion cards don't tend to run hot anyway, this shouldnt be a problem. Otherwise, the case has good cooling - my hard drive sits at around 35C in this case, where in my old shuttle it was at 50C. The processor rarely gets above 40C with the zalman cooler on it, too.