I, for one, prefer turbine over piston sooooo much. I did turbine transition in Schweizer 330 in 5.2 hrs including exam flight. At that time I totalled 78 hrs. I would beleive that B206 would be a breeze with the R22 in your backbone. For me, B206 was somewhat messy as it was my first two-bladed (they're a bit wobbly).
The 500 will never leave you dissappointed in anything but passenger space. It's just dynamite fun to fly. I agree with previous posts - you need some hours to cope with the speed of that little thingy! I did my 500 about a year after the 330 and distinctly remeber that I flew very carefully the first 20 hours or so. Type rating time was 3.8 hrs (it's very simular to 269/330).
As for time spent on a type rating... The flight course for B206, approved by the Swedish JAA, states - i believe - a minimum of 4 hrs of flight, and a range of manouvers to cover. Most people seem to get it right in 4 to 6 hrs. Ground school was two days of poking around in the machine and taking a written exam. If you feel that the UK is expensive, give Proflight north of Stockholm a shot. They're very good and hold an FTO with B206, AS350, Enström and A109 types in it. Very good! (
http://www.roslagenshelikopterflyg.se/pfeng1.html for info in English)
Have fun - a torch on the roof is so good!