well i dunno maybe you can ask A123racing.com to send you a few 6.6v packs to see how they measure up like...for publicity purposes? I dunno lol.

Thedunemaster from Ebay seems to sell them for half (or more) than a123 does. Might wanna get in touch and have him sell ya a 4600 6.6v pack. I dont see it being over $60 from him. His email is [email protected]
he says "If you have any questions or would like to request a battery configuration you don't see here, just drom us an email and we will get back to you ASAP." so there you go. Just ask him for http://www.a123racing.com/racingpacks/hs2s2p.html that configuration and maybe he'll give you an estimate? :P

anyways, yeah im rambling and just wishing for something that isnt likely but hey if it happens it happens! Keep up the good work.