The ramps I bought from:
http://www.okoffroad.com/stuff-ramps.htm
I had to shorten them by a couple of inches to make them fit, and I painted them black so that they blended into the tire carrier etc.
The blocks were custom made, and drilled to accept the Hi-Lift with two bolts and four guides. I also changed the mechanism that makes sure that the tire carrier does not open, as I felt that it might not be able to manage the extra weight.