I would have one big concern with that drivetrane. What are the rear end ratios?
I have seen trucks with a similar setup and even with the two speed rear they were geared for a maximum speed of 45-55mph.
If the one that you are looking at will run decent highway speeds at a reasonable RPM then I would get pretty excited about it. Enough so that I may try to discourage you from buying it... Just let me know where it is for sale