Why not start a "what car next" thread as everyone seems to love telling other people how to spend their money.
Just put your budget & some of the essential criteria like performance, drive train, n# doors etc etc
I know all the cars available as I have a problem with browsing cars for sale weather I'm looking to buy or not. Will have a look at rs4s again but got a feeling the weight would be to much!
I wouldn't get too fixated on the weight side of things imo, ...take a look at it's power to weight ratio, take one for a drive and make up your own mind.
Plus your not going to be on track all the time so for its main purpose of getting you & the family around it'll be more than adequate imo. Good luck with your decision.