Need tow harness and advice on towing.

[tedbull]

I mounted a tow hitch on my 90 loyale 5 speed 4x4. It is the type that bolts to the bumper and thru the pan with a 1 1/4 reciever hitch. I will be towing a 4x8 utility trailor(300 lbs) with two dirt bikes (600 lbs). I will be traveling 1500 miles round trip. I still need lights. Anyone have a good source for plug in or splice in wiring harness for my rig? Also will I need a power converter or anything else? Anyone got pics of there tow setups with trailors and loads towed for referance? It seems like my car should handle this no problem. I know that it will slow me down for sure.