I've seen the hvmaxx esc handle 5s2p, but that is slightly different to an evx2..
Parallel setup has nothing to do with voltage (normal cell count)- its just an easy method to double the runtime & reduce the voltage droop under load ( a stock brushed setup isnt gonna pull alot of current regardless).
Your esc is setup to use a pair of packs in series (2x 2s for example), so you will have to either rewire your esc to take a pair of 5s packs in parallel, or just do like Linc said and use a normal 2s Life pack on each input.
You seem to be over-thinking things- its nowhere near as complicated as you imagine- read my tutotials page, should help abit:
http://robotwars.00server.com/tutorials.html