Well, incase you don't know, the 700E has a 7x clock multiplier and the 733EB has a 5.5x clock multiplier. Thus for each MHz you up your FSB with a 700E you will gain 7 MHz processor speed, whiile for each MHz you up your FSB with a 733EB you will only gain 5.5 MHz. I would buy a 600E or 650E (depending on how lucky you feel

) cB0 stepping processor, and overclock it to a 133 MHz FSB. The overclocked 600E would be running at 800 Mhz and the overclocked 650E would be running at 866 MHz. I would think you could get a 600E cB0 to 800 MHz with a retail heatsink fairly easily, if you don't feel comfortable with putting custom heatsinks on your processors.
As for the motherboard, I would suggest getting the Asus CUSL2 rather than the P3V4X. I'm not saying the P3V4X is a bad motherboard, I just think the CUSL2 will be somewhat faster, and should have less conflicts with video cards, and things like that. You can look at Anand's review of the CUSL2 here:
http://www.anandtech.com/showdoc.html?i=1274 and find out some general information on the motherboard. Also, if you look at the benchmarks on page 4 of hte review, you'll notice how the CUSL2 outperforms the P3V4X by 4.5% in the SYSMark 2000 test, 6.8% in the Winstone 2000 test, and 6.0% in Quake 3 Arena.
Also, I would suggest to get good quality PC133 RAM so you can run it in CAS2 mode rather than CAS3.
If you decide not to overclock at all, then I would suggest the 733EB.