Well after the great success I (finally) had converting my Wonder, I'm now mapping out the power system for my Somethin' Extra. It's already built, I originally was planning on putting a Saito .91 in it, but that was a bit much, and, well, I'm tired of messing with nitro engines

On to the details/goals:
AUW (less power system) 63oz - includes radio system but no Rx batt - planning on either BEC or UBEC
Looking for, let's say Aerobatic+ performance, I built it for 3D stuff, but I'm just out to have fun, so I'm not planning on takeoff-to-land 3D flights.
My goal is at least 100W/lb, you can never have too much power.
Hoping for >1 thrust-to-weight

So, with that in mind, I'm aiming for 500-700W to power the thing. So here's what I've mapped out so far:

4S Lipo will give me the desired power if I draw 30-45A. From looking at specs and playing in Motocalc a bit, it looks like an AXI 4120/14 is what I'm looking for, capable of 45A bursts, and according to Motocalc, with a 14x8 will give me 45A and ~91oz of thrust.

So far so good (feel free to critique if I've made a flaw in my plan so far ).

So now on to the questions.

ESC:
I'm looking at topping out at 45A, so I was thinking a Phoenix 45 would fit the ESC bill. Normally I prefer headroom, but this system is going to be expensive, so I'd like to save money where possible. Will a Phoenix-45 work, or maybe I should say, is the headroom of the Phoenix-60 necessary? Considering, most of the flight will be pulling <45A, I'm thinking the 60 would not be necessary.

Batteries:
This is the trickier part, since there are a number of options:
1) Kokam 3200HD 4s - 64A capable, more than enough, actually one of the lighter options - AUW would be ~88oz.
2) PolyQuest 2600 4s2p (these are the 10c) - 52A capable pack - about 2.5 oz heavier than the Kokams, but a little cheaper
3) PolyQuest 2600N 4s2p (these are 12c) - 62A - about 4 oz heavier than the Kokams
4) PolyQuest 3100N 4s (these are 12c) - 37A cont, but they're rated to ~50A burst - but 3oz lighter than the Kokams and much cheaper

So, considering the "fagility" (for lack of a better term) of lipos, I'm inclined to go with Kokams. If I got that 4s from 2x 2s packs, there would be the added benefit that I could use the Kokams in (2s) my Wonder also. And with the 64A rating, I could also use the 4s pack in the A-26 I'll be building . Oh, and I'm figuring on an Astro 109.

I guess this is mostly a sanity check, any comments would be appreciated, thanks