If it's CPU and GPUs go with a 60mm thick 360mm rad in the roof and a 60mm thick 240mm rad in the bottom, for GPUs only one 360 in the roof will do. Either the XSPC RX, Phobya G.Charger or Alphacool UT60 rads would be right for the job.
This kit would be perfect for your CPU, comes with everything you need except Coolant. You just need to add 2x GPU blocks, a 240 rad and four more fittings to be able to do your GPUs as well.
I'd get some better fans than the ones it comes with though because they aren't very good, something like the Scythe GTs 1850rpm or the new Noctua NF12s.