Oh, I did not relise you were thinking of one ? Thought you just had a quiry ?
No probs, If you have the facilitys then its more satsfiying if you make bits yourself.
If you need any help let me know. I may get told off for this but heres a picture of one of my tubular ones. The winch version looks the same other than having a winch basket between the chassis rails.
Heres one of the winch version I am working on