Homemade jibs are my specialty, my backyard has like 3 rails and a box.
The best rails, in my opinion are actually those toy store rails. Factor X recently went out of business, so i went down to kb toys and bought 5 6ft rails for 10 bucks each on clearence. they are cool for small places, you can put them just about anywhere, and for 50 bucks i got 30 feet of rail.
But, i also like to build my own stuff. metal pipe with fittings are your best option, besides welding your own, that is. just get an 10ft pipe, some elbows and a couple of t's and little pipes and put one together. you can make all kinds of stuff with the fittings. kinks, flat rails, the sky is the limit with just a little imagination, and they are quite easy and can be taken apart for storage very quickly.
Heres a rough drawing i made in photoshop, just do the same on the other end.
PVC is your enemy. They chip, slide like crap, and yes, catch your edge. Painting will do no harm what so ever. Terrain parks paint their rails every year. The top layer is usually gone the first day. Your edges will not dig into the paint.
As for the drop in, build something and make the top layer with some treated ply, paint it, and then seal it with a wood sealent. it will last for quite a while.