Need some Tire help

Hey guys, I looked around but couldn't find any recent threads matching my current dilemma.

I've got an '06 GT with the factory 18" premium wheels. I'm way, way, way overdue for new tires and I'm having some problems finding what I want. The factory tire was a 235/55/18 BF Goodrich. Currently the car is running factory suspension, but that will change within a few months.

I've had great success with Pirelli PZero Nero M+S's on my 02 GT that I'd love to get them again. Unfortunately, I can't find them ANYWHERE in 235/55/18. So, I need some advice. I live in Florida, so cold weather/ice is never a problem. I need the stickiest possible tires I can get, but they also need to have some dexterity in wet weather.

Option A: Can anyone suggest a different tire size that might be available in the Pirellis? I'm not opposed to having different tires in the front and back, I've just never done that before so I don't know what sizes to get.

Option B: Does anyone know of a tire comparable to the Pirelli PZero Nero M+S that I could get in 235/55/18 instead?

I really appreciate any help. I've been trying to figure out a solution for the past month and I've come up with nothing.

Thanks.

The tires on my car are definitely 235/55's. I've looked over Tire Rack's site, but I was looking for 55's. If going to a 235/50 isn't a big deal, then I suppose I can take another look.

I just don't have much experience with tires, so the different ratings are a little confusing to me.

It's funny, I can wire an entire car without a diagram but I'm clueless about tires.