Most any local driveshaft shop will be able to overhaul your driveshaft. Note that means driveshaft shop, not a general purpose shop or garage that will just send it to a driveshaft shop and then mark the price up.
You might want to double check that the driveshaft is not being over-extended or over-compressed by the motion of the suspension. This could quickly damage the slip joint or other components. The proper fix is to lengthen or shorten the driveshaft by a currently unknown amount.
Looks I will go TW's. GREAT reviews here and it is what my rear shaft is one my YJ. With that said... when I measure... do I measure from the middle of the yoke or the end (where U joint connects)?
I have 5 shafts from TW. He's taken care of me on custom orders (beyond the "normal" custom) and have been easy to work with. The non-greasable Spicer joints are the strongest and last longer in wet environments imho.