Hey vDanee
Here's my two cents worth. I bought the A7M266 board. It is a bit more expensive, but rock solid stable and gets good reviews. It's only drawback is that you cannot adjust the multiplier, only the FSB. However, I have been able to drive my Athlon 1333 chip up to 1450, using the FSB adjustment. I strongly agree with those who suggest a power supply with a bottom intake (which will pull hot air off the CPU underneath). I would suggest the Enermax 430watt supply, or Sparkle (I have the 400 watt model AMD approved, but it does not have the bottom intake). I feel that the extra $20 for 400+ watts is well spent, as your future needs are never certain, and even if it is overkill, your voltage is more stable if the supply is not being even the least bit stressed. If you are a hardcore overclocker, the A7M266 may leave you somewhat unsatisfied. I am using the Taisol copperbottom heatsink (I have removed and replaced it 5 times in various experiments and never hurt my CPU, mainly because the heatsink is large and evenly applied pressure with a very good clip system. I also may be very lucky...fate favors the foolish. But the heatsink was attached by my vendor with thermal tape (it looks like a pink square of silly putty, and it was not doing a good job. I tried Radio Shack paste and then Silver Arctic II, and the ASII did only a little better (maybe a degree or two). One time I put too much paste on, and redid it with the good old half a pea of paste evenly smeared on the die, and the prepping of the HS by wiping a thin layer on before putting it on the CPU. I also suggest another improvement. I bought a 80mm to 60mm adaptor which is like a funnel that allows you to use an 80mm fan at lower rpm and still move more air over the heatsink than the excellent Delta fan that is a real screamer. These adaptors are found at Plycon.com, and you would want a good HS with good quality clip to hold this extra bulk in place. BTW, I own a PIII system also, my first bought in 1998, which is a HP8485Z, using a 440BX motherboard by ASUS. It was very stable and I liked it a lot, but decided to try AMD and have not been disappointed. This new system rocks and with a VisionTek GeForce2 Ultra card (oc'd with Coolbits to 275/500 Mhz) it scores 4740 on 3DMark 2001, which makes it no slouch
If you really want to rock and roll, the GEForce 3 units are reporting scores in the 6000s, but I have read some reports of strange artifacts and other quirks with the GF3s, so I decided for now on the GF2 Ultra. You'll have a lot of fun making your own system and being free of the shadowed bios training wheels on stock systems has its rewards (and its headaches), but you will learn a lot.
Can't we all just overclock?