[RC-Monster Mike]

You have it right. A 2s3p is 7.4 volts and 12000mah if the cells are 4000mah. You could also get two 4s packs and run them in parrallel (so 8000mah and 14.4 volts), or two 4s2p in parellel(so 16000mah and 14.4 volts). What cells are you looking at? I have the Kokam cells (few different sizes) and I like them because they offer a high amp draw for the weight. I also only run for 5 minutes most of the time, so I am not trying for runtime so much as weight savings(runtime is a side benefit, though!). Pollyquest makes some nice packs that offer nice discharge rates and a higher mah per ounce than the Kokam cells (lower amp draw per ounce, but higher mah per ounce). With the Polyquest packs, you could probably get a 15 minute main in at around the same weight as your current set-up (so a pit for the 30 minute main).