Ryan, on the SPAL USA site:
http://www.spalusa.com/pdf/30101509_SPEC.PDF#view=FitH it shows that fan drawing around 10 amps.
If you want to set them both up on the same feed, same relay, etc. I'd suggest a minimum of 12 gauge TXL or 14 gauge teflon insulated, silver tinned copper from McMasters
http://www.mcmaster.com/#7304k151/=dkcc2d) I've been using this stuff for my ignition setups and it's great. The 14 gauge will handle 45 amps, and it's rated to nearly 400 degrees. Due to the teflon insulation and the silver tinning, it's much stiffer than the TXL, but it's more durable too.
For fusing, I'd stay away from the typical little ATO blade automotive fuses as I've had them overheat and their plastic housings melt, and cause the fans to fail. Get a large round glass fuse, like the type used for stereo installations, or a MIDI fuse like this:
http://www.mcmaster.com/#9180K88. I have no experience with circuit breakers - perhaps others can chime in here.
For a relay, I'd suggest a 35 amp weatherproof type, again sold by McMaster. This will either be a Bosch or a Tyco:
http://www.mcmaster.com/#9672K44 with a weatherproof socket and 12" pigtails:
http://www.mcmaster.com/#8228K44
Or if you want to be really safe, go with one of these Bosch 75a relays, with anti-kickback diodes (the diodes will help save the contacts from arcing when opening):
http://texasindustrialelectric.com/relays_0332002156.asp
The only disadvantage of the 75a relay is that its life is rated at 100,000 cycles at 75a resistive, or only 40,000 cycles at 60a inductive, while the 35a relay from McMaster is rated at 10,000,000 cycles. I've used both, and for my single 16" fan in the Supra, I used the 75a relay and it's lasted 8 years and counting (although in reality I rarely drive the car)
But if I were doing it again, and I was doing a pair of fans like you, I'd probably install SPAL's PWM fan controller. It's rated up to 30a, so it should be able to drive both fans together as one:
http://www.spalusa.com/store/main.aspx?p=itemdetail&item=FAN-PWM-V3