Balancing is not an issue if you mark everything before disassembly. The nut is usually zero balance, but you have to mark the shaft and compressor wheel in relation to each other.
Honestly, rebuilding a turbo is a pretty straightforward process, but then again I've also had a few apart. I rebuilt the turbo on my truck myself, it's been on the truck for 10,000 miles now with zero issues. However this really depends on the overall condition of the turbo, if it's pretty good but just has too much play in it, you can probably do it yourself.
If you do need a balance lots of places can do that for you. I had an outfit called Gpop's Turbo Shop (you can find them on google) balance a turbo of mine a few years ago for $90 which included the cost of return shipping.