creating hl2 models can be the frickin easiest thing to do (ever!)
with SOFTIMAGE|XSI, goto valve's collective (or whatever it is. :S)
and try a search on SOFTIMAGE|XSI, read the tutorial, it's like 5 clicks and you make a model ready to skin!! it's easy, you choose a bunch of features (masculant, cocasion, female male)!!
go get it now!!