I'm converting a glow .46 size plane. Here's my set up so far:

KMS 4120-06
Waypoint 70A Speed Controller
13/8 prop

The plane weighs in at about 8 lbs. I need to know what my best options for a battery is. I have one, 4s 3200mah pack. I was wondering if it seems too ridiculous to link 2 of those in series and use them in this setup. Also, I'm open to exploring the option of a 5s or 6s pack but if I can get by with what I have, that would be ideal.