You can't go wrong with that solid Seagate 250gb, the crucial ram, and the E8400. As for the motherboard, both use the newer P35 chipset which benchmarks very well and supports the new 1333mhz bus and 1066mhz DDR2. I've always been an Asus fan for years and I can't comment on Gigbyte or Abit brands from my experience.
$150 for the Abit after Rebat and $100 for the Gigabyte. The Gigabyte does not support RAID or firewire (but you can always buy expansion PCI cards for this if needed). The Abit does offer 6 SATA drive compared to the Gigabyte's 4. Both have onboard crappy audio, but I see you've got an X-Fi.
Are you looking at a RAID setup anytime in the future? Or do you have a need for more than 4 SATA drives? I'd save $50 and hassle with rebates and get the Gigabyte. Some of the Abit reviews commented on not supporting the E8400 completely (whatever that means, who knows what some of these reviewers know).
I'd give you a Asus board to use, but apparently their newer boards in the $100-150 range suck.
