I just went through the same thing last year, but with A048's. I knew I was going for SS and talking with BWR, the hardcore bar IS what you need with stock springs. But, to use the bar to its full potential you need adjustable shocks. I was not able to get my car to rotate with the LSS shocks (except for when I did something stupid and caused snap oversteer). Since my ohlins upgrade, I can dial in a neutral car with 175/225 AD07's or 205/245 A6's. I'm still working on my set-up to make it as fast as possible.
If you are going to stay with stock shocks, I would go with the street bar if possible.
Also, the stiffer bar is to correct for the inside wheelspin coming off the corners and it also helps with transitional response. This is at the cost of understeer in sweepers. If you set up the corner exit properly you can get on the gas sooner, and allow the car to push out to where you want it to be, working around your problem.