For that sort of current you could use Deans Ultra or Sermos connectors all around. Personally I am a devotee of Gold Connectors (from www.aircraftworld.com) - Dave stocks MP Jet 2.5mm (50A) and Jeti 3.5mm (80A) at about $1.50 a pair.

Try your 1600 pack but I THINK in the long run you may need a larger battery pack - 1600mAh @ 25A will give less tha 4 minutes run time. I'd go for an 8-cell KAN 1800 NiMh High Rate at only 33g [1.1oz]/cell or Sanyo HR-4/5AUP 1900 at 32g, or Sanyo HR-4/5AU 2150 at 35g. These should all be able to supply 20-25A or so without trouble.

Cheers, Phil