suffix siege or suffix deep cranking. both I have used an are one of the strongest lines I have used. Strong not from pulling in huge fish but from being so hard to break off my line off snags an that off of 6lb test line really strong for a mono. The suffix deep cranking is a mono that sinks an is more focused towards crankin an getting your cranks deeper than regular mono would. It actually does get them down maybe even a couple feet lower than spec. The deep cranking the only place I have found it is on tackle warehouse fairly cheap for 10bucks a spool of 300yrds cant beat that. Might work best for you being that you primarily would be trolling.
read some of the reviews. Dont know how big of a fan of suffix you are but check it out.
http://www.tacklewarehouse.com/Sufix...html#multiview