A pair of the 3700 mah packs would be good, you would need to make up a parallel adapter using the connectors you choose.
Getting up around that size with a 4074 or 4082 I'd run a 2000-2200kv motor and a t-180 esc. Depending on how well it's set up you should see at least high 50 mph with that setup, a bit more once you get it dialed in. Start with about a 42mm prop for the first runs until you get the CG and strut setting right then you can probably go up to about 45mm, but keep an eye on the temperatures.
That should be a very reliable setup with enough overhead on the esc to allow for a few first run setup mistakes. Many people have used that exact setup on cats about 36" with great success.
Some of my 4s boats use a pair of 4s 4000mah packs in parallel, smaller ones like my Motley crew I run a pair of 2s 5000mah packs in series, much smaller boat and motor though.
My stuff is all setup to run about 3-3.5 minutes, about race length, any longer and the heat starts to build up, could easily go down on prop size, lose a bit of speed and get longer runtimes.
For the batter adapter most guys solder two sets of battery connectors to the battery leads of the esc, then connect both sets of + and - leads from the batteries to the esc. SOme brands of high amp esc come with two sets of battery wires from the factory for this.
Either the Swordfish 200 or T-180 esc are pretty popular, in our group we've had no issues with either. There is also Castle if you have deep pockets, but top end escs!
I'd also go with Leopard motors, there is another type available now called TP, lately I've been reading about people having issues with the rotors.