I didn't think the panel R&R was that bad. There were a few tricky spots though, like the seat belt mounts. Then again, when I did mine, I had three full days to completely strip the interior, dampen, and put it back together. I think the key here is taking your time to do it carefully and correctly.

As for speakers in the rear, personally, I don't think you need them unless you frequently have passengers in the back seat. You'd be surprised how good you can make a set of components in the front and a sub or two sound, even on a tight budget.