Good practise John. I tend to go with flat 1/8" X 3/8" spars, mounted about 1/8" or perhaps a little more, to allow for covering sag. I feel that by using these two spars, seperated as much as I can, offer better strength, with less weight, and allow for the use of adjustable leadouts.
In either case, the reultant structure will be better than the original.