Rear main seals are not hard to do. Dirty job? Yes. Read-up on how to do it and tackle it. My preferred method is to drop the pan. I would slap a new oil pump in while it's all open and accessible. Take a look at your bearings (especially the one you have to drop to get the rear main seal) while you in there. Bearing wear can tell you many things about what is going on; or not.

The valve cover job is also an easy one. Just don't break the rear valve cover vent while you're disconnecting the vent hoses. Those vents get VERY brittle with age (a personal lesson learned), and don't over-torque the cover bolts. It doesn't take much to make the seal and an over-torque condition will just squish the gasket out.

 

good note on the over torque, an over torque can also snap your stud very easily lesson learned the hard way lol