There's a resonable amount of info out there on wheel weights, but don't forget tire weight too. I am looking at some replacements rims and tires for a Dodge Spirit R/T and have decided to go for 16" diameter rims. My searches have produced rims ranging from 29lbs+ per rim down to 16.3lbs per rim (7" width). 225/50/16 tires range from 29lbs down to 23lbs. Guess what...I chose some wheels at 16.8lbs and tires at 23lbs...combined weight 39.8lbs..much better than the original unresearched option which worked out at 54lbs...ouch!
www.tirerack.com have plenty of info for most.