Re: oil, gas options?
No reason to use anything other than a full syn 0W- or 5W-40. I have 46k on my roadster with no issues. Both cars have their oil/filter changed in the fall before winter hibernation, and neither really do more than 4-6k of driving per year. I generally alternate 1/2 tanks between premium and mid-range on the n/a but I use exclusively premium in the SRT6.
I also have 227k miles on my 2003 Audi A6 2.7T (bi-turbo) and have used Mobil 1 0W-40 exclusively every 7-8k miles. Still runs fine although the turbos are starting to leak a little. I think that is a decent testimonial to syn oil.