A few things I'd like to point out here:
The P4T533-C simply sucks because the FSB is limited to 150MHz.
Secondly, the I845G is a great chipset, but the P4B533 is based on the 845E not the 845G.
Most reviews I've seen compare the VIA P4X333 or the 845G to the SiS 645 or 645DX reference board.
As for performance overclocking, I recommend the P4S533. It has the most overclocking features, save the ability to lock the PCI/AGP bus. It supports up to 1.9V VCore and 2.9V Memory. It has the 4:6 FSB to RAM ratio, that allows for 400MHz+ memory at 133MHz and above. At that rate, it would outperform all other competing DDR motherboards.
However, if you're going for an Intel chipset, I recommen the IT7. It sports up 3.2V memory and the unoffical ratio to run memory at 350MHz+ on a 533MHz FSB. It's an extremely good overclocker.
You might also want to look at the BD7II or the BD7.
If you're going RDRAM then get the ABit TH7-II and some 40ns Samsung RDRAM or Kingston PC1066.
If you're going DDR RAM then get the P4S533 and some DDR400 or some Samsung PC2700 and overclock that. With some extra voltage, 450MHz is not unheard of at a 150MHz FSB.
If you're going to go with the BD7 or TH7-II, make sure you download the latest BIOS before overclocking. There is a cold boot issue with these boards when you lock the PCI bus and do some extreme overclocking. The latest BIOS solves this issue.
I don't recommend the P4B533 because it's not a major contestant among overclockers as of yet. I have heard quite a few good things about the P4B266-C however. I'm sure the P4B533 is a good board but I haven't heard too much about it in terms of overclocking potential.
Generally, with a DDR RAM mobo, you'll want something that provides high VCore, and high VMem so you can overclock the thing.
In terms of stability, you can't go wrong with Intel chipset based motherboards. Outside that, I've heard nothing but praise about the P4S533. It does have that 4 bank PC2700 limit but that's nothing a little extra voltage can't work around.
With that said, if you really have your eye on a 845G motherboard, then I suggest you look at the Abit BG7, I've heard some good things about it. I don't recommend VIA.
Sorry, if this sounds sloppy, but I'm really tired.
<b><i>"A penny saved is a penny earned!"</i></b>