Blue smoke and burning oil

Hey guys, I've got a 2003 Honda 300ex that I've had for a little while now. I bought it knowing it needed a rebuild, but I've been riding for two years so far without major issues. The time has come to rebuild, but I don't know exactly what I should be looking at. I was hoping if I listed my goals and budget, you guys could point me in the right direction. I'm not sure if the cylinder is trashed, but I only had 80 psi when I compression tested the motor so it's either the cylinder or the rings. I did a wet test and the compression spiked which tells me it's not a valve issue. I was looking into the big bore kits since I'm pretty sure I will need a new cylinder anyway, but I see it looks like they need some machining to fit the crank case. I'm looking for more acceleration without sacrificing too much top end. Would it be possible to get my current cylinder bored if needed? Or are the walls too thing to accept any boring? Also, what combo of sprockets would be best to help out acceleration without killing the top end? I'd like the quad to still hit at least 45mph (I weigh 210lbs).