Something sounds wrong here, DT. The "contractor" will do the wiring if you provide the panel? Politely decline - this guy might not be an electrician. Electricians will know exactly what to buy for your requirements and how to legally install. Call in two or three electricians, get a price, labor AND material, and let one do the complete job. Don't concern yourself with voltage ratings, grounding, method of power distribution, etc., - just tell them you want a dedicated circuit from a subpanel. A good electrician will take it from there without even blinking.
Keep a wary eye towards anyone who asks you to buy electrical parts, except, of course, any specialty outlets or wiring. Chances are they won't be licensed or have no standing or credit with supply houses. (Also applies to plumbers, carpenters, etc.)
FYI, honest, well-established contractors will never ask for money up front for materials or "mobilazation" costs. Anyone who does this usually cannot manage their money and will spend your downpayment to finance someone else's job.
Keep a wary eye towards anyone who asks you to buy electrical parts, except, of course, any specialty outlets or wiring. Chances are they won't be licensed or have no standing or credit with supply houses. (Also applies to plumbers, carpenters, etc.)
FYI, honest, well-established contractors will never ask for money up front for materials or "mobilazation" costs. Anyone who does this usually cannot manage their money and will spend your downpayment to finance someone else's job.