I wouldn't get an underwound Rebel Yell. It really will still balance nicely with the 8.4 k Alnico IV Mule, seeing as it's also Alnico, warm and very punchy. And for the long run, you're going to want to have that extra bit of gain. If you wanted something less hot, then I'd advise going for one of the classic hot 'buckers instead of the RY. Good luck!