Drysuit wrist seals come in various sizes and types! I've found Gates (Hunter) suited me quite well - it might be worth having a try of different suits at a dive show and ordering spare seals from the manufacturer who produces those which fit best. Suit repairers rarely seem to stock varying seals unfortunately, only size differences from one manufacturer.
My wife uses one of these soft neck bands below her latex neck seal - its designed for use under the latex seal which causes skin damage without it - which is made from some really bizarre material. It works very well and has the added bonus of being warm, but she is finding that the latex seals are failing earlier than they used to and wonders if there is some chemical interaction between them.
In emergecy we've used neoprene straps held over latex seals with velcro (essentially neoprene wrist seals which can be tightened and held in place by velcro sewn onto it. This works on neoprene seals and probably would on latex too.
I've had to fit new wrist seals to my current in-use drysuit over the last few weeks - one is too tight (absolutely dry but little blood seems to get past it, although after 20 dives it is slackening a bit) and the other was a rush job when a large hole appeared in the other seal (I'm still baffled about how). Despite being stuck on in between dives both are solidly on. If in doubt carry spares and glue!!! Oh yes, and I've tried dry gloves but prefer thickish neoprene as I couldn't get on with the dry gloves which took too much damage.