You want to go with the 5/32 for suspension use. Grizz actually had it break on him in that application, despite the strength rating. That almost certainly has to do with how tying knots in cording reduces the effective rating. The 5/32 rating is high enough that it has proven to be reliable.
Spyderline is a fine choice. Amsteel Blue is also popular on this forum, but either will certainly do the job.
Bookmarks