Good to know front replacement can be done, if done right. Thupertrooper is right about finding the parts(rears), I started looking and gave up after awhile. Not seeing them without more digging.
A friend with a lift and oxy-acetelene is a good friend! Game changer. 237k is awesome, very possible to get alot more life outta her. When I was looking for PF in the fall 2018(wanted one for years, bro in MI had 05SE) the market was pretty slim,(b/c these are great trucks) 2011/12's were scarce; good find, especially the LE. 08SE replaced my 03 Trailblazer with 244k, that the ohio salt flats were REALLY eating; she was unzipping quick. No major issues on it other than typical GM nonsense (except steering rack, but with that mileage, SOP) Other than all of the darn corrosion, PF WAY easier to work on.
All of the bolts needed; especially the elliptical cam adj. can add up, but not too bad in the grand scheme of things. I highly recommend an anti-corrosion product called E.C.K.; Electrolysis Corrosion Kontrol. (by Van Nuys, you can order it directly from them). It's consistency is like toothpaste. I use it everywhere, as it lasts a long time and doesn't get on everything like copper or nickle anti-sieze and is safe on plastic&rubber. I smeared it all over front skid plate last winter (it was rusting really bad; and the few dry times in Ohio were spent catching up on other things, I didn't have a window to paint it) and it's still good. Makes life easier, especially on fasteners. Been applying on frame etc. here and there right over rust; just buying time, and re-applying as needed.(doesn't wash out but can be removed with normal rubbing alcohol or usual solvents. And no I don't represent them, it's just that good of a product
I think a lot of dealers make their money off of parts and service rather than sales. Just my opinion based on what I see. U-joints on mine are coming up sometime this year I'm sure, as they appear original. Dreading that as they look like solid blocks of rust. Wonder why your PF is hard on joints. Just another quirk on these trucks? Pinion/yoke bearings O.K.? Drive shaft in-phase/ balanced? Or is it just the steeper drive angle b/c shorter wheelbase. At least u-joints are reasonable.
Yeah, and the "propeller shafts" (I'm stuck in the past, I call them drive shafts, and "final drives" to me are differentials
) are VERY expensive. I would look into aftermarket or even fabbed ones first if the price is right, if that's REALLY the issue.
Sorry about long reply, I tend to ramble. Hope you can get it done for reasonable cost and she can remain in your fleet for many more moons. Good luck on the rear, those new parts will feel great on the PF.