Hello,
I was being offered a GK76a in MINT condition with 11000km on the clock
Anything in particular I must be afraid off? Are most parts available or are they hard to get???
I'm 1,80m. Will the bike fit me or will I have to be very very very flexible???
How much fuel does it consume? (normal sportive driving style).

Just sold my SZR660. I like light bikes with a good handling. So this one might be a good choice for me
(p.s. also own a Muz skorpion sport and a Triumph Street triple R)

They are ok regards consumables.
Regards other parts you are reliant on the breakers.
The bikes are 20 years old now so the gsxr is like any other 20 year old bike, so long as you take this into consideration you will be ok.
Riding is rewarding or a pain in the ass, depends how you like your bikes, you have to work them hard.

I like to work hard, as long as I'm being rewarded for it.

What about my 1,80m. Will the bike fit me alright ? I'm 38 years old, weigh about 72kg and I'm in a good shape.

5.10 dont seem too big.
Im 5.10 and find the 400 ok.
Yep, you get nothing until they are above 10000 rpm, great fun as you can wring the F'ing thing without getting into license losing territory.

I'm kinda like 5,9 ft
But the Yam SZR660 fitted me alright. Also a bike that is wanted by 5 ft-ers

The bike I'm interested in is 100% original and in showroom condition. I'll take close look at it this wednesday.

Im 6ft and while its more cramped than my nc30 it isnt too bad, i did about 120 miles in one day back in september and i was acheing like mad the next day, think that was mostly to do with riding it round a go kart track for most of the afternoon