I'm partial to twins and like the TL and SV quite a lot. The I4 superbikes are awesome machines, but lack a certain visceral feel of the twins (as well as the low-rpm power that's so handy on the street). Incredible track bikes though.
The ninja 250 is a solid bike and quite durable. Overheating is rough on a motor, but there's a decent chance that it didn't suffer too much damage. If you are really lucky a new hose and coolant and it might be ok. If not, it'll probably just need a head gasket and the head surfaced, though more sever damage is possible if it was ridden till it simply wouldn't go anymore.
FYI helmets are supposed to be replaced at least every 5yrs as the styrofoam inside breaks down and they loose some of their protection. I spent $250k filling my head with info, a $500 lid every 5yrs isn't a big deal.
I often replace my lid more often as I tend to ride a lot of miles. 30k a year isn't unusual for me. I also keep a few sets of gear in different place so I can fly in and ride without having to check luggage - I've got a set in Colorado and FL and here with me in VA right now and will send a set and spare bike to SoCal soon (going through the bike now - raced it in Vegas to Reno last year).
This is the bike I'm fixing up to send to SoCal - ~40-50mpg of moderately spirited dirt riding. ~30ish mpg at desert race pace.
This one lives in Co full time (wish I did!). About 15-20mpg at race pace and maybe 30mpg at a moderate closed-course pace.
My dad keeps this 919 in FL for me to ride when I visit (and I've been known to tour on it a bit - buzzed to Colorado, the black hills, deals gap and back a couple years ago). This pic got me on the front page of killboy. Got a low of 32mpg going rather fast into a stiff headwind while heavily loaded, but normally see around 42mpg riding normally at sea level and can approach 50mpg at colorado altitude
The bandit 1250 I only owned for a month, but put 9k miles on it in that time. It did around 45-47mpg at sea level, but really liked altitude and never did worse than 50mpg in colorado and usually was near 60mpg.
Well that's most of my recent rides - I don't have pics hosted of my TL right now (it was on a different server that died recently).