Jamsport don't turbo the st150 engine or the 2.3 unless i've missed something in the last few weeks?

The st150 is tried and tested at 200-250 brake so i'd go for that and where have you got your info from saying turboing it'd be cheaper than supercharging it? Cheapest supercharger kit is £3200 iirc and the cheapest turbo kit was just over 4k last time I looked??

there are loads more supercharged ones than turbo'd ones aswell!

i'd probably say the turbo option could get you better MPG as you can drive it 'off boost' on the motorways. I used to get between 30-35 mpg out of my car when I commuted in it :P