Looks like you're interested in carving & stamping. Get the best tools you can buy with the money you've decided to spend. If you realize later that leatherwork isn't for you, you can sell the good tools.
Barry King has a great set of stamps for $400. Yes, it's quite a bit of money to invest in for a beginner but it'll be worth it if you keep at it and if you don't you'll be able to sell it.
http://www.barrykingtools.com/sizelist.htm
Don't wanna spend that much? Check out: http://proleathercarvers.com
You might consider a stitching chisel instead of a pricking iron or overstitch wheel. You won't need an awl with the chisel, just punch it all the way through.
Swap the razor knife for a rotary blade. Olfa is a good one. I found mine on sale at Joann.
You'll need a finish over your dyes. Might try Fiebing's Tan-Kote.