I've just been through this exercise after being recommended to use a rubber coated net by a mate who does comps etc.
First mistake not to make is (like I did

) is if you're looking at coarse fishing nets:
- make sure it's DEEP enough so the fish can't jump out - rubber nets are much stiffer (technically less "drape") so remain "open" more.
- Avoid the "hair net" small mesh - makes the net act like a scoop.
I came across this
Fox Predator Net 24” - £12.99 : Johnson Ross Tackle, The Best Specialist Carp Fishing Tackle
and have been pleased with it. As it's designed for pike etc it's double depth of many coarse nets and more than big enough for v large stockies/doubles. @ £12,99 its a steal.
I've mated it to a telescopic carbon 2m pole (£10), but also have an old alu pole around 1m I can use. My only thought about boat use is if the carbon pole is so light it may blow off the boat in a hoolie.