Juan,
If you're upgrading for Lomac then personally, I'd get this cpu...
http://www.newegg.com/Product/Product.asp?Item=N82E16819103529
With that 4200 X2 you're giving up 512 megs L2 cache and 200 mhz clock speed as compared to the 4000+ San Diego core. If dual-core is important to you then yeah, that's a fine choice but Lomac doesn't do anything with dual-core.
That mobo you listed is gonna leave you stuck with AGP! Plus, it has a VIA chipset which isn't supposed to be as good as an Nforce (or Uli in my case) board. I'd stay away...go with the AsRock board.