What airsoft gun should I get?

I have finally realized that hobbytron sells cheap worthless defective guns that brake after a day but because of their stupid return policy i'm stuck with 2 pistols i bought. They are giving me store credit and am not getting a pistol so I am going to get something that may actually work. I am not going to pay any more money on this company than the store credit i have so the only thing I can afford is a refurbished electric rifle with good fps and I found 2 guns that may work. 1 is the Refurbished Electric Tactical M4 Assault Rifle FPS-315 Airsoft Gun and the other is the Refurbished Electric Double Eagle M805B1 CQB M4 Assault Rifle FPS-350 Airsoft Gun. I am leaning on the double eagle because of the higher fps and the only drawback is that the other gun has 50 more round capacity which isn't much difference. Does anyone know what gun I should get or how I should spend the store credit? Please help me...