Uh... Wings3D ? I didn't care to start using it,
because I didn't find something for converting the results - but you might try 3DExplorer (which a link for can be found in the modding section over at gamewarden - it's in a sticky about modeling I think) or whatever else there is to find.
About UV-mapping though... should you be able to find a solution for the converting problem, you could (for a very simple start) use cubic mapping in Lithunwrap (link either in the modeling-sticky at GW or the one over here at HLP - don't really remember).
Not that that LU couldn't do anything better - it can. But as far as I understood you, you don't yet know how it works, so I suggested something easy to start with - excuse me if I should have misinterpreted your remarks
.
As for the model... Doesn't look bad
. I'd say it's relation to the Orion is somewhat visible - but I currently miss any pics of it's engine/aft section... well - either that or it's aft section is severely missing engines...