Ok.... Take this from a guy who's a scrounger, bit of a wheeler-dealer and eclectic tinkerer...(my self that is)...
Get out there and start looking about.. travel the block and look around in empty lots, construction areas(DONT STEAL ANYTHING, ASK, THEY'LL MOST LIKEY GIVE IT TO YOU FOR FREE), ect.... if your brave enough go to some small shops that work in stuff your looking for...
This is the way of the pick..... Always keeping your eye out.....
That one above, is actually a good start for look at an idea if a welder it totally out of the question....
So... post what you got..... get serious, and we'll help you get rolling...... keep in mind its going to be a little bit, and you must be patient.