I have two exterior walls that need insulation. one particular wall has just the studs and the bricks behind them, so no way of putting sheeting/tar paper/vapor barrier, etc.so, i am thinking of just putting sprayfoam.is there a place online where i can buy supplies so that my contractor can do it? 

I am doing my cladding on the outside, with closed foam insulation.  

Looks like the electricial wiring is original two cloth-insulated wires, although the kitchen and bathroom have three-prong GFI outlets.

We install flex and ductboard systems, insulated metal sweats worse than these materials. 

Plus, $650, $650, $620, $620 are pretty high rents around here. the majority are around $500/mo.The building has a 7 yr old roof, newer furnace and hot water heater, insulated windows.

I have sold placed for $165,000 more than what I bought them for, but completely redid the house, roof, insulation, siding, etc.

I would add mineral wool or batt insulation to the walls for sound. 

Remove all the drywall and insulation.  

No serious structural damage but subflooring was bad, standing water etc, doors had to come out, new insul across a good 10 joist, ek!.  

Everything, everywhere.Also, it's incredibly difficult for an inspector to approve work that he can't see - be prepared to tear down drywall to expose wiring (and is the insulation fire code approved?)