Well, I can tell you where NOT to get them.
Armored Motorcycle Jacket & Other Motorcycle Gear
I would not recommend them for something long term. I bought a full pair of leathers and the seams are coming apart just about everywhere they have touched the track. Yes they work, yes they are nice heavy leather, but the seams suck.
I have had to repair them after every race so far. With leathers you get what you pay for. Double folded glued seams would be good, but mine are just cheaply stitched, and once the stitch wears through in one spot the whole seam opens up all the way up.
One thing worth mentioning though, is that if you wick some super glue (model airplane CA glue) into the seam's thread, it will prevent the whole seam from opening up if it wears through in one spot.
I now do this on my leathers, my shoes, everything.