Thanks, going to look into it all and maybe give the longer ones a go and try to roll up the sleeve a little. I need the bigger sizes for my stockiness. Presumably cutting the legs and sleeves isn't a good idea but will see and be open to all options.
Yes I have seen the mass starts at London online. It looks like and reads like from the threads here, that there are waves of maybe 300 throughout the day?? Starting from the water. I will be treading water chilling at the back (tip from Holgs book), just hope I don't get caught by the speedsters in the wave behind me. That won't be fun and I don't want to go the really long way round by staying on the outside I had better just practice more in the weeks ahead. I'm not a great swimmer, but am determined to learn the front crawl and be good enough to give that a go for the 750m.
I saw the mass start of Frankfurt IronMan on Youtube, that one really did look freaky and full on - a real definition of mass start!