Mike,
Since you're UK based - I'd join a BSAC/SAA club if I were you and have a word with the Dive Officer/Equipment Officer. The club structure is a good one to learn in for UK conditions but you have to be patient in finding a club that you feel comfortable in.
IMHO a refresher is not sufficient for UK diving if you were tropically trained. The conditions are harder and you have to learn about local sea conditions/customs. BTW I've assumed you want to dive in the UK because Plymouth is a good location to dive

and you mentioned drysuit.
A good site is
www.bitz.fsnet.co.uk - the main thing is to get a decent drysuit and undersuit and then go from there. One thing you will need is a DSMB (blob to us Brits) as it's use is practically mandatory on boat dives and you need to get training on how to do it safely and you'll need a torch. Regs - those of us who have Apeks regs love them (I love them!)
Gloves (5mm for winter 3mm for summer if you tolerate cold well)
Hood - you'll need one - I use a a Beaver and it's ok
Cylinders - 12litres normally and you'll get a good price from Kent Diving.
Dive Computer - see the bitz website - I use a Suunto Vyper and I'm happy with it.
One thing with UK diving - be prepared for early morning starts and serious p*ss taking. And above all give it a try and stick at it - you'll find a learning curve but when you get a dive like I had a fortnight ago with sea temperature at 13C and 10 metres vis it'll all be worthwhile.
I hope I've given you some reasonable advice there and wish you luck.