wire or mono?

i do a lot of conger fishing from the boat,i was wondering what would be better for a trace, mono or wire

Mono all the way.

should i use a knot or a crimp?

i prefer using 200lb mono and i crimp it

I dont go as heavy as that myself, I use 130lb mono and knot it. No issues as yet with being bitten off.

what size hook for wreck fishing?

Mono and carefull attention to knots. Never lost a conger due to mono.

200lb mono all the way. i was a bit annoyed at myself last year when using wire cos if the conger takes the hook deep the wire cuts the hell out of the corner of their mouths and leaves them in a sorry state

what size hook for wreck fishing?

8/0 - O'Shaughnessy's are a good pattern or something similar.