Replying to Prophet 130s...to use brakes, or not to use brakes...

I got some Prophet 130s and want to put the Axial 140 (pivot type) on them, they'll be for BC use and some in-bounds fresh days. Question is: I'll have to bend the brakes mad amounts for them to fit, and probably have to pay an extra $45 for the wide brakes to begin with, is it worth it to do that? Will the brakes even have an effect on a ski this fat in powder, or will they most likely just cruise down them hill anyway? The other option is the snowboard leash, but I don't like that idea for obvious reasons...but would the coiled type work ok, and provide enough length when stretched so as not to end up in me getting seriously fucked up but the ski(s) in the event of a release?