I can't tell you which way to go.
I'm assuming you have the brushed Blackout SC and not the Pro Brushless version. I haven't had luck with brushed motors. My brushed motors, that I was trying out, ran hot no matter what I did to my RC's gearing. I quickly gave up the idea of running brushed motors. I read a bunch of reviews/threads on many RCs, and my general consensus of brushed motors is, they are not made to take abuse. Plus, everyone wants longer run times, and that just adds to a motor's stress level.
Whichever way you go, I'd suggest going with a brushless RC.
That charger you got is only good for NiMh, and NiCd batteries. If you look to part ways with your Redcat, and find something with LiPo batteries, you would need a new charger.