Stock fronts, wider rears,Sports Pkg. - effects?

Azroadster

I am coming up on 16K on the OEM Bridgestones and I will be replacing them with Hankook V12's. I played around with the Discount Tire size calculator and I think I would like to run 305/30's on the back, but stay with the stock 245/40's on the front. Going to a 275/35 on the front would, IMHO be too wide. I am running 15mm spacers on the front and 20mm in the back. Several threads have pictures of the 305's on the rear with 20mm spacers and I really like the aesthetics of the wider tire out back. Other wider sizes in the front throw off the rev's too much for my taste with the exception of the 275's.

First, are there any issues with going that wide in the rear and staying stock up front such as more pronounced oversteer and secondly, are those of you running 275's up front and 305's in the rear having any negative issues?

I think I checked all of the pertinent threads relating to this, but I would like to know from those that may have gone both ways before I make such an expensive decision.

Thanks,

AZ Roadster