Sourcing interior parts for a '79 C30

[5Tractorguy]

I have to re-do all the door weather striping, window felt seals, vent window seals, felt window tracks and vinyl floor mat. Who has the better parts out there?
I ordered a mess of stuff off RockAuto last week for the drive train/engine, but I was hesitant on these interior parts due to quality and how well they'd fit (especially the floor mat).

Also have to look into floor sound deadener and A/C vent hoses for (what I'm told) is the aftermarket A/C system.

Also, does anyone know where to get 2 piece saddle blanket seat covers? All I can find are 1 piece covers, Walmart was the only one who listed a 2 piece cover... for the healthy price of $160.

Any help/direction is appreciated!