I like the pc1 aswell but its the hd 5970 on second pc which is pulling me, looking at benchmarks i7 920 only gives about 10-15 fps boost max compared to amd's 965 where as 5970 is nearly twice as powerfull compared to 5870 so about 40-50 fps boost at simular price margin
What size monitor? The 5970 will only matter if you have a screen large enough for it to matter. If you have a single 1680x1050 monitor I'd go with computer #1 as the CPU is much better. The CPU does matter in gaming.