Bought an '85 S10

Just got it today and it's the base model 4 cylinder/4 speed I'm guessing. It has no power windows or door locks, no power brakes or steering, no A/C. Runs good, but just loud. It's a fixer-upper for sure. I want to possibly add power steering and brakes. How difficult and expensive would adding these mods be? Also would like to quieten the exhaust down. It kinda sounds like an import car with an aftermarket muffler, kind of a "buzzing" sound...I just want it to run quieter if possible. Any suggestions on exhaust systems or maybe even a certain muffler? Also is there a good place online that I can get replacement stock seats, or at least seats that will directy fit in the truck without any modifications. I would actually prefer a stock bench seat. The guy I got it from threw out his old worn bench and replaced it with seats from a Tahoe I think he said. Only one of them bolts down because they are too wide for the both of them. They both "fit" inside the cab, just not properly. Or would I just be better off looking at a junk yard, and possibly re-upholstering if necessary? And is there a place online that sells the dash? Not a dash kit or cover, I want the real dash panel, this one is worn and cracked. I've looked for seats and a dash panel online but haven't yet found a place that sells them. And one last thing (for now) I posted a question a few days ago about putting a 91-93 style grill on this truck. Is that possible without body modifcations?