Your wheel pattern should be 4x410 Contact Sunco Motorsports in vendors for brake pads. 10w/30 for the oil. Preferably a synthetic. Not sure exact capacity on the 4. Also see Sunco for spec on capacity. Sounds like a possible vacuum leak then. I would check and or replace the line they pinched off first. I bought Bosch replacement blades by length that have the universal mounts. The horn is stock. I found one at a salvage yard in a horn pile that was the same. Not sure of a kit for the power steering , but quite a few have installed so someone should help out here.
The manual doesn't provide much in the way of maintenance so don't sweat not having one.