A bit off topic but :
1. The best neck-warmer is not a neoprene one on the outside of the suit but a fleece tube with a drawstring on the inside of your neck-seal. Polar Bears (Tel. 01566773654) sell them for about £10. Maybe Lou could do them cheaper, being into the DIY thing
2. There's no need to spend a fortune on an expensive undersuit. I wear a 100 g Thinsultae undersuit bought from Kent Divers (postal order) for £70 all year round. With a single layer of thermal underwear in the summer and double in the (Swedish) winter, I'm never cold.