They're both pretty much the same as far as I can tell. Do any of you have experience with either of these board and are able to advise on which is better, or suggest a comparable Mobo in the same price range (<$85)?
Go with the MSI board, I was a huge ABIT fan(all most a fanboy), but receantly they where involved in a merger. So I wouldn't go with an Abit board, any time soon, because I wouldn't want it to end up haveing horid support 6 months down the road when the merger takes place.
I have 3 MSI boards, 845PE and 2865PE and never had a problem. Easy to update the drives and BIOS with their update program and their web support is pretty good as well as the documentation you get with the board. I think some of Abit's 939 boards are/were having problems with USB. There was discussions on their forum. Been a month or more so it may be fixed, even possible it was another mfg but pretty sure it was Abit.
I've used both and had good results with them. A friend of mine who works in a PC shop says they usually RMA Abit boards the LEAST. However, I think either would do well for you. For $85.00 you could also go with the Epox EP-9NPA3ULTRA which comes with the somewhat more refined Ultra chipset and SATA II support.