Mid size & compact trucks have been done before - so you're OK there. In fact, if you're building for a 40 mile range, you pretty much HAVE to build a pickup truck to hold the batteries! (Assuming you're going to use golf cart batts, which most people do.)
Step one, if you haven't done it yet, is to head over to the EV Album to see what others have built that interests you. Most people lay out what components they use and how much they cost:
EV Photo Album: Our Electric Cars on the Web