Jardines are kinda loud, i dont know if theyll pass the strict EU tests.
Id advice you to stick with one of them Japanese or European brands.
Yeah the question has been asked many times. dont sweat it tho, you wont be the last.
Arata it seems has the best power, most agree Hamaguchi looks the best.. and stay away form Yoshimura, (personal prefference)
D&D are deep toned and loud
Jardines scream like no other..
Sato's are loud but ive never seen one on a 600RR in person...
As far as sound, go on youtube.com and search, you'd be pleasantly suprised at the amount of sound clips for 600RRs that are on there.
Oh, and a big Welcome. yeah...
you got a guy over there who is a member i think hes in London also who is parting out his bike.
Check out the goodies, hes a cool cat, im sure he'd be of some help to you... and he has a exhaust for sale, maybe he'll cut u a new neighbour deal