RE: Would this work?
Scale Cat, did I read that right that the model you want to convert is only 18 inch wingspan? If so I'd suggest you stop right now and go find the bigger foam gliders that are up around 3 foot span. To keep a small model like an 18 inch span one down to an acceptable weight requires highly specialized and not cheap super micro equipment. Even a lot of the now fairly common micro gear would be too big and heavy for such a small model.
Doubling the model to 3 feet may not seem like a big change but it quadruples the wing area and at the same time the "scale effect", sometimes given the term Reynolds number, gets far more favourable with the increase in size. So the bigger model can carry far more than the doubling of the size would suggest. And even more than the quadrupling of the wing area would suggest.
Don't be afraid to use Lnewqban's information about the tape hinges for full span application. It's not going to come out too heavy at all.
While pull-pull systems do work well they often come with some funky geometry problems that if you don't watch the ratios of the setups can result in slack or overly tight cables that cause trouble. For your first few models I'd suggest sticking with wire pushrods and single sided control horns. It's far more simple to set up and avoids some fussy adjsuting of angles and stuff that pull-pull can result in requireing.