Figure a ball park of $1000. IMO, go for the BlueOx baseplate with the removeable tabs.
I use a RoadMaster telescoping towbar. 5000 pound max. If I were buying new, I would investigate the "ReadyBrake" towbar. Really interesting. I would choose the "ReadyBrake" over all the other systems that require battery power and, like the above post from CA TRAVELER can give you problems you don't need.
You can get the brake light/rear running light diode kit or go for the magnetic lights. I've used both with no problems.
But you FIRST must read the OWNERS MANUAL for your car. If it says you can tow 4-down...go for it. If it says you cannot tow four down, you're done.
g'luck!
