996 Deep Snow Tires and Wheels - 17x7 all around

[bustedbelt]

I live in Vermont and the staggered tire packages for the 996 17" rims were not appealing. Going on a limb, I purchased an extra set of front 17x7" twists, and then stewed over spacers. Ultimately, they were mounted with Hankook iPike studded 205/50/17, and I mounted the fronts and test fit the rears. The 17x7" fit fine in the rear, leaving the outside of the tire slightly inboard.

Handling and traction are amazing - with exceptions. You have to be on your game on the highway and the car wallows on off/on ramps in the dry. On snow and ice covered gravel roads, the car floats predictably, transferring weight to the nose helps the fronts bite for better turn in and rotation under braking.

I am still learning the car (I just bought it in late December) and I am wondering if spacing the rears back out will help with highway stability. I've never had spacers on anything but a Suzuki Samurai so comments are welcome.

Also, should I space out 25mm with big spacers and extra bolts (I think the stock fronts are +39 and the rears are +55), or go the easier route with 12 or 15mm spacers?

Scoll to 996 section of this link, which lists 39/55 for the front and 49/55 for the rear - though I am not sure why there are two numbers. (Porsche Wheel Fitting Chart and Fitment Guide | Alloy Wheels Direct)