I owned a 2007 Miata and a 2008 RX-8 owner. I would still have the RX-8 if my situation hadn't changed and I could still afford/justify putting gas in it, and I would still have the Miata if I didn't need a 3rd seat for my kid.)...
Spend some time researching the RX-8 at
http://www.rx8club.com/
The RX-8 isn't for everyone. The car gets poor MPG, uses/burns oil by design, and requires specific care and feeding to keep it running right. If you can live with the quirks and idiosyncrasies of the car, you will be rewarded with a fantastic driving experience that will put a smile on your face every time you get behind the wheel.
There is nothing like the rotary's smooth 9000rpm redline, and the shifter operates like a bolt-action rifle. The rotary needs to be taken to redline every time you drive it (after a proper warm up) to keep the motor in the best running condition. It is a car that needs to be beat on to be happy.
I am not saying "don't buy a RX-8". I am just saying educate yourself and understand what you are getting.
If you don't need more than 2 seats, get a 3rd generation Miata. It is built on the same platform as the RX-8, and handles better with a cheap set of springs and sway bars because it is lighter. The Miata does everything the RX-8 does at lower (legal) speeds without the idiosyncrasies and needs of the rotary engine.
If you are worried about safely, add a roll-bar to the Miata. You will get added piece of mind, and you will be ready for track days at your local venue.