Thanks for the feedback guys, 145 Lbs sounds like the way to go then, and right enough at 15-20 quid a spring they don't really break the bank so I can always upgrade again if needs dictate down the line.
If you're interested here's a wee pic of it at standard height, all the glass and chrome is back on now, but still a bit to do.
Any more feedback appreciated.
Cheers,
Phin