Depends on your level of experience, and what you want to do. Fly it Controline, and you have the problem of fuelproofing, installing a belcrank, pussrod and making a working elevator. Fly it Free Flight, you have the problem of fuelproofing, getting it trimmed out and quite frankly I think a Cox .049 would be too hot for it. If I had to suggest, I'd point you towards the Brodak profile models for controline. You will still have to fuel proof the model but I think it would be a better match for that engine. They don't have a BF109, but they do have a nice Zero, Mustang, and a Wildcat if you dig the WWII types. But if you're new at model airplane building, start with something that has a lot of the dynamics for flying that kind of model already figured out. In my opinion, I think the combination you're suggesting, Cox .049 and 16.5" Guillows scale model, would be challenging even for an experienced modeler. You are wise to be doing your research first. Checkout the Brodak 1/2A models here. http://brodak.com/control-line-kits/...eries.html?p=1