have answers/suggestions for a few of these.
1. AMD is just fine, and the CPUs are considerably less expensive. Used to be that if you were into CAD, or other heavy graphics apps, the Intel Chip was the way to go (unless you were a MAC freak) due to the then better floating point system in the Intels. Now it doesn't matter, as AMD has really upped the ante with their newer chips. Go for the fastest board you can for the money you want to spend, then get the CPU to match. AMD is way ahead of Intel on the 64-bit front, so I expect it would be an excellent choice.
2. AGP is about to go the way of the dinosaur. Limits to bandwidth are cause of its pending demise. PCI express gives more bandwidth, thus any graphics-intensive apps will operate smoother and faster. PCI Express is more expensive now, but offers upgradeability that AGP won't. In any case, the MB and Vid Card go hand-in-hand. There is no backward compatibility. I suppose if you look hard enough there is a hybrid board out there with both, but I haven't seen one yet.
3. "SLI" is Scan Line Interleaving. All about the way your Vid Card and Monitor interact to create the display on your monitor. Standard scanning lays out the information one row of pixels at a time, while SLI lays it out in alternate rows. A few years back (like the last time I actually up-graded any hardware) SLI was avoided by gamers due to the latency introduced by doubling the time it took to display an image compared to standard scanning. With all the advances in hardware these days, I suspect SLI won't be an issue. But I could be wrong. Check with one of your local PC gurus, or Google around for probably better advice on this subject. Or play it safe and avoid SLI. (yeah, this was really helpful, wasn't it?
4. Can't say much here other than I'm currently using 478 and it has worked well. But I expect I'll need to upgrade sooner than I wished just to keep up with the RAPID advances in graphics in these g*****n addictive apps!
5. SATA (Serial ATA) is fast becoming the norm for most MBs sold now. It's touted to be much faster than even Ultra ATA. The HD had traditionally always been the slowest internal item in a PC, but speeds have increased tremendously during the last couple of years. SATA adss to the cost of a board, but will be well worth it if you can afford it.
6. No comment. I'm stuck with Intel for now.
7. Everybody has a preference as to brands. I've owned ABIT boards that blew all capacitors even with a good UPS, though they came very highly recommended. Others have had zero probs with them. ABIT, ASUS, and Gigabyte all have pretty good reps, but like all mfrs they have some models that just plain suck. Once again, check with your local guru, or a dependable internet vendor for the most reliable models of any particular brand.
As with anything, stick with what you know. If the ABIT in Tricia's PC has been reliable, go with it.
7. FSB ideally should be less than or equal to the MB bus. If the chip has a higher FSB it creates a bottleneck in the data flow. And good performance is all about eliminating bottlenecks when possible.
Do some serious shopping so you can get the most for your money. There's alot of crap out there, so be careful. I really hate to see a grown man cry.
I hope I've been of some small help, Willie. I just haven't kept up on this the way I used to.
Temp here is a bit warmish at 30°C.. 
