Hi fandango.
I cook & eat a lot of fish but never in a curry,IMHO i find fish to be very unsuitable because of its very subtle taste & texture & cant for the life of me understand why it is used for Curry making, but like other things in life preferences with food is a very personal thing.
I think this is a particularly tasty Curry & perhaps some of the very large King Prawns would be OK, but please do read through the recipe as it will make for a multilayer many faceted Curry,that on reflection would work,go for it matey & please do post your results & opinion of this particular dish.
Yours .....DARTHPHALL.....