In general i would suggest that one always choose a newer vehicle over an older one. However, from your description, both of these probably have many issues. If you have no mechanical or woodworking skills and need something to live in immediately, it might be wiser just to buy an s&s for now, until you have more funding for a bus. Also remember whatever motorhome you purchase may need a transmission or some other expensive part when you are traveling down the road, so it's wise to always have $3000. or so before you set out.
If you have the ability to do a conversion yourself, then for 2500 -3000 you probably can buy a 1990 or so bus. The 91 thomas pusher that i bought last year after selling my coach bus was cheap. I think my net cost for it was around 2600 after selling the seats, and they filled the fuel tank up before i left.
If you are looking at a bus, don't be afraid to offer the seller something like 60% or so of his asking price for immediate cash...