Hey.. I have done that with my COSMOS 2. 2 Rads on the bottom in parallel configuration. It's a tight fit but can be done.
Outside air -> Fan (Push) -> Rad 1 -> SPACE -> Fan (Push) -> Rad 2 -> Fan (Pull)
* For the Space in the middle, I use another fan to draw Outside to blow down the middle of the rads (to cool the hot air from rad 1 a bit before going into Rad 2)
MY Overall setup is
Koolance Pump/Res -> Parallel 2x 240 Rad (Push+ Intake & Push pull) -> Pump MCP655 -> Parallel GPU -> 1 x 240 rad (Push Pull) -> 1 x 360 rad (Pull) -> MB chip -> CPU -> VRM -> PUMP/Res.
(Pumps are swiftech, Pump/res is Koolance RP-1200, Fittings are Koolance+ EK, GPU is EK + Bridge)
Current Flow is 4.3L/M
Ambient: 29C (Hot as well where I am now)
CPU Block temp: Idle 36C Loaded: 55C, (i7 3930K)
GPU Block Temp: idle: 33C Loaded: 46C (GTX 680 in SLI)
*Fans are at low/ medium speeds, and system is slightly over clocked.
Liquid cooled Cosmos 2 (no mods to case) * Asus RIVBE * i7 4960K OC @ 4.6Ghz * Corsair Dominator Platnium 64 Gb@ XMP2400 * 3 x Asus GTX680 SLI + EK WB & Parallel Link * 3x Samsung F2380 * * OCZ Vertex 4 256Gb * 2 * 5 x WD Black Raid5 *Intel 80GB SSD * 2 x Swiftech 655 pump + EK D5 tops * Aquacomputer Aquaero 5 Pro + 3x PA2 Ultra + Multiswitch * Koolance components [Rad ( 120, 2 x 240 parallel, 360) + Res/pump RP-1200 + Asus RIVE WB + 370 CPU WB + Flow meter INS-F 17N] * 11x CM Blu LED 90CFM 19db + 2x XtraFlo + 2x XtraFlo Slim * LOTS of fittings (EK & Koolance) + QDC
* Pump/Res -> GPU dual SLI -> D5 pump -> Parallel 240 Rad -> D5 Pump -> Fan CTL WB -> 120 Rad -> 360 Rad -> VRM -> CPU -> MOSFET + MB WB -> Pump/ Res