I am building a Kangke Laser 2000 and need help with which batteries I should get. I really would rather not get the expensive Lithium Ion batteries unless there is a major difference besides weight because my plane is already tail heavy and I could use the weight for the CG. I was thinking about using Nickel Metal Hydride. I am going to need 3 batteries (ignition, servo, and receiver).

Here is my plane setup

DA-50
5 Hitec HS-5945MG
1 Hitec HS-5925MG
1 Futaba 3305
Electro Dynamic Optical Switch for ignition (edr-107)
I4C Isolator

I am looking to get batteries that will allow me to get at least 4-6 fifteen minute flights with. Please let me know what you all think and would get? I am looking also see what sizes I should get. I appreciate all your input!!!!