I'll play devil's advocate here. Having major health problems and SSI disability your only source of income really doesn't sound like a match for RVing. RVing, even part time, can be very expensive when you add up fuel costs and campsite/lot rents. Since you're looking for an older RV, repairs can also be very expensive. Sounds like you're a DIY kind of guy but what happens when you're camping 300 miles from home and something breaks. No tools or parts available to fix it.
If you're just looking to get away from city air and spend time with your kids, you might want to consider setting up an older TT on a seasonal site. Just tow it there once, then use a vehicle that suits you and your kids to go back and forth for mini-vacations.
