RE: need more power!!
I went with a dual IPS, A model I think, and was vey happy with it. The dual IPS will add much more power but not that much weight. The dual IPS will also fit on your existing mounting stick. You will have to turn it sideways and it will not fit under the cowl properly. I just left the cowl off. Eventually I cut the stick out and mounted it 90 degrees so it would fit in the cowl. It will climb good and loop without having to dive first. My battery was a 350 mah, 8 cell, nimh. I think your battery will be too heavy, but go ahead and try it and see.
I tried an EPS-300 but it was way too heavy for the wing loading and it landed like a brick. To get a good CG the batteries had to be put way too far back and they would not fit inside the fuse.
One thing - shortly after I installed the new motors I went loop crazy and folded the wings (a couple of times) and finally destroyed them. You must consider the wing mods if you are gonna fly it hard.
Good Luck!