c20 Air bags????

[DTerry]

Hey, I have a 1970 gmc c20 with leafs in the rear. I plan on using this truck for a daily driver and to haul a racecar in the summer. I heard that alot of you guys that haul cars or trailers use bags in the rear. I was woundering if its worth getting bags or should i just get lowering springs and shackels. I saw this link http://www.airride.com/productinfo/airoverleaf.asp, if you guys think I should get bags then are these the right ones to get?. Thanks for all the help its appreciated.