100lb. test should be just fine since that's about what's in all the kits and none have failed to stress yet. I think the 45lb. stuff is cutting things a bit thin, though.

The "times 10" rule is what I usually use if I'm scratch building something and go to the ultra safe side of things. If I'm building a kit or arf I uses what comes with the kit, including the Wild Hares. Never had any problems with using what comes in the kit or matching same. I think the kevlar stuff is massive over kill and costs too much.