120GB is pretty much the sweet spot for SSD boot drive as 240GB SSD is still quite costly, 120GB is plenty enough to install the other applications you have mentioned.
You can try other retailers like Amazon if you want to go with Ivy Bridge CPU, the price should be about the same.
CPU: Core2Duo E7400 Wolfdale 2.8Ghz LGA775 65W
MB: Gigabyte GA-EP45-UD3R LGA 775 Intel P45
RAM: 2x2GB OCZ Platinum DDR2 1066 Dual-Channel
GPU: EVGA GeForce G250 512MB 256-bit GDDR3 PCI Express 2.0x16
PSU: OCZ ModXtreme-Pro 600W PSU
Monitor: HP 2511x 25-inch LED Full-HD monitor