Great advise from the gang. While we all think the D675 or STreet Triple would be great, we also understand that you are looking at the entry level with more common sense than most riders. You are in the right engine size that will hold your interest for more than a summer. If you can get a 600 Katana cheap, that would be a good point. However, take a look at the DL650 (V-Strom) as it is a very good all rounder that offers some wind protection for longer rides. I actually was away from cycling for about 10 years and got back into it with a Bonneville. I like the retro thing, but also did not want to get a faired bike until I had some time on a bike. Things have changed, bikes (and cars) stop much quicker now. Take a look at the link on Suzuki bikes here
http://www.topspeed.com/motorcycles/...0-ar42933.html as they have dual disk brakes and are fairly reliable. Have fun and be safe! Hope to see you on a Triumph!