For .049 size models Ihave found Spiderwire a lot less troublesome than messing around with .008". It's a lot lighter than steel lines but (in my experience at least) a little bit more "Draggy". You need to use specific knots to tie it otherwise it can pull through under load, the Palomar knot seems to work well (Google it if your not sure how to tie it). Ihave flown 049 size models on 15lb with no issues. Make sure you get the braid though not the monofiliment. Available in plenty of colours (So easy to see and not trip over) and very "robust in use", No chance of kinking even if you step on it or manage to get a knot in it.

TTFN
John.