I have lipos in my 120 planes. I can fly an entire weekend without thinking about a recharge. They are 2600mah but that's not even the point - two days of flying and I put the battery on a charger, and it only requires 550ma to recharge. Lipos are just much more efficient, not to mention they weigh less (yes, they still weigh a few ounces less even with the regulator).

I was just at a pattern meet in NJ and every glow powered plane I paid attention to had a regulated lipo system.

You can go to tech-aero.net and look at some regulators. Feel free to send an email or call if there is a phone number. I spoke with one of the guys that makes the regulators (they are made to order) and he took the time to talk to me on the phone and explain everything. You can tell them what you want to do and they will probably make it for you.