So the question still is for myself, what is the best vehicle to convert, or shall I say the most practical for the average american who drives less than 30 miles one way to work and has a budget of only 10,000.
If you are talking <30 miles one way to work, we'll assume 60 mile range is needed (for cushion and varied driving conditions). From my understanding, you will have a very hard time to get that range in a conversion for 10k. I would dare to say it can't be done (today). Since you are looking for such an extended range, I thing the pick up or van is a good idea, becuase you'll be carting around a lot of lead. Pay special attention to the Curb vs GV weight to make sure that you can add enough batteries to meet your requirements. In addition to the possible lower drag of the minivan (don't know for sure, but I'm going with what was said before), another advantage in the van is you can put the batteries very low and center - probably a little more than what you could in a pick up bed - and it's already protected from the elements.
An S-10 might be good choice b/c you can get adapter plates cheaper - as they are already being produced for kits and you should not have to pay a design / one off premium for it.
Same is true of the small (Geo Metro for example) cars. If you comfortable with a tiny car, then that might be the way to go - but make sure you can put enough batteries in there to do the trick. Maybe talk to Mr. Cloud - he packed 101 miles worth in one for the last Range Rally.
Best of luck John!