I have a 09 Gsxr 600, and LOVE it. Since you have never had experience it will be hard to ride each brand to see which you like the best. Everyone has their own opinions on which is the best.It looks like a decent deal. I know the powers have good grip, they just don't last as long as the Road 2s or 3s.I would recommend getting Farmers insurance. They were the cheapest for me having speeding tickets in the past. 112 a month for full coverage. I ended up switching it to State Farm under my girls name for 43 a month. I know Geico quoted me around 4,500 a year though. 20K= miles is actually not that much. It has a lot of life left in it. Most of the time you see very low miles on bikes are from either being dropped, and they got scared. Or they took out a loan and can not pay it.
Check the brakes,front forks. Ask when the chain was replaced.Take it for a full throttle test run first, or bring someone with you capable of bringing the RPMs up. Ask the seller to leave it cold until you get there, and let you start it up.
Trust me it's easy to say you won't haul ass on it, until you actually feel the rush. I think everyone who has ever bought a bike has said it, including me. Just be smart. Wear gear ALL THE TIME! Sweating does not hurt. Road rash does. Sure I look like a stupid blue power ranger, but I challenge any guy in shorts, and tank top to jump off going 50 with me, and see who ends up the most hurt. I had a wreck not to long ago. Was ran off the road, and slid down the side of the street, If I wasn't wearing full gear, including motorcycle boots. I would of defiantly ended up in the hospital.
Oh yeah,
Call a rehab because you will get addicted!