Want some input on new CPU purchase

Hey first post here.
Currently have a Palo XP1600+ on an ASUS A7N266-E with 2X Corsair 256MB PC2700 DDR.

Built it in 2001, now I'm married and don't spend as much on my "toys". Want a cheap and easy upgrade til prices on 939-64's and MB's come down. ASUS' site shows that I can go as high as a XP2600+(T-bred 266FSB) with the highest standard BIOS (my current) or can go as high as a XP2400+(Thorton 266FSB) with a beta BIOS. Newegg shows both T-bred and Thorton 2400+'s for $69. Board and chipset (first nForce) are made for 266FSB, but my memory should handle pushing it.

1.) Anyone know which may OC better?
2.) Should the fact that I would have to use a beta BIOS matter significantly?
3.) Are Mobiles interchangable? If yes, should I think about going M-XP?
4.) Any suggestions on a good price/performance air cooler for my new CPU (currently have a Volcano6 keeping my Palo at 40C)?

thanks for any input

OK first up the Thorton is a Barton with half its cache stripped out whereas the TBred only has 256KB L2 cache to begin with - the Thorton is some circumstances can be modded to get back the extra 256KB of L2 cache that was disabled but there are no guarantees. Overclocking I would say it was more likely dependant on when they were produced as to which one is better - a newer cpu is more likely to overclock higher - however all things being equal I would lean slightly towards the Tbred. As for Beta bios well that may mean some instability issues but you dont know that until you try it. What specific mobiles are you looking at - if you mean Bartons then you could probably put one in your mobo as it is a 133FSB at default and with your board's FSB limitations overclock primarily with increasing the multi. In terms of good cooling have a look at the options over here.
http://www.overclockers.com/articles373/socketA.asp

What do you need a new comp for? 1.4 pallys not bad unless you like to play modern FPS like far cry...but even then it's much more helpful to look into a video card.

I think he is only buying a new cpu not a whole system.

Well it still stands. Fine get a mobile 2400 for $77 (will it work in his board) or a t-bred ~50 for nothing gains really.

I'd rather buy a weeks worth of beer. Or in his case a nice dinner for the lady.

Hmm dont know about that a XP1600 Pally is likely to be around 1.6 - 1.7GHz a Tbred at 2.3Ghz (quite possible) is a 30 - 40% upside - hardly nothing gains - A Thorton modded to a Barton is even more so.