If you want regulators, check out the Tech Aero regs (
http://www.tech-aero.net/ or F3Aunlimited.com). They are very light and very reliable. I use two 450mah battery packs for my receiver and two regulators. If you wanted just one you could do an 800mah battery.
I know you said you're looking for a BEC but you also said you purchased a regulator you weren't happy with. I have been using dual tech aero regs in my contest plane for a few years, and use a single reg in my sport plane. They are great, and light.