If I may make a suggestion, I think you are limiting yourself too much by saying either socket 754 or P4. I would include the 939s in that as well, you can get a 939 board with AGP and the price isnt that much more than a 754 board. The CPUs themselves have little difference in price.
Anyway, this is a good 754 motherboard for the price
http://www.newegg.com/Product/Product.asp?Item=N82E16813138247And this one is much nicer, and I believe faster. Plus I like Abit's overclocking tools.
http://www.newegg.com/Product/Product.asp?Item=N82E16813127190Abit has always (in my experience) been rock solid, and I've heard good things about it from hardcore overclockers. I have had good experience with the Biostar stuff (what I am currently using in my Socket A setup).
As for the P4 stuff, I'll leave that for someone who actually has experience with them and can recommend one for you. I havent owned a Pentium since...........well, actually, I've NEVER owned a Pentium processor (except for a few I took apart and trashed). Good luck!