RE: balsa usa phaeton 90
My Phaeton 90 got coaming tubing from lowes plumbing section... it comes gloss black and adhered very well with canopy adhesive. I drilled a 5/16 hole in a piece of balsa and inserted a #11 blade and pulled the tubing through the hole to slice kerf.
Another trick for installing the wind screen on the thin plywood foredeck is when cutting out the windscreen, add four tabs on bottom edge (two forward and one each side). The tabs make it very easy to cut slots for the tabs and slide the windscreen into them. I then heated small T pins and locked the tabs from within and applied some glue. It made the wind screen installation a piece of cake.
I wished I'd gone with quad ailerons... the roll rate is ok but when doing an Immelmann turn, the roll is very very slow and occasionally will even balk at rolling out.
The Phaeton 90 is one of the best ground handling planes I've ever owned and it has beautiful climb outs and landing glide slopes. If the engine is yet to be chosen, I'd consider a small gas motor like the Zenoah G-20 or Brilleli 26. This airplane has a lot of drag and a bigger motor than those isn't going to do much more for it than add weight.
Flying... if there is a head wind, it will need power on landing, again because of the high drag. If no wind, the idle will need to be low to get it down. Don't try an Immelman at low altitude until confident it will roll upright. Stall is straight forward.
I'm running a rather small converted weed eater on mine and it flies like a scale biplane. A G-20 or Brilleli 26 would provide better aerobatics with fuller loops.
I also had to brace the landing gear from spreading... this was done with 1/16 stainless cable and cable locks. To install this, I used stiff center spring enclosed by heat shrink tubing. The wire provides a spreader at 3 inches of height above ground. I've DuBro air tires and an Ohio specialties tail wheel bracket. A quality tail wheel bracket will go a long way towards exceptional ground handling. A bracket that allows the wheel to tilt even slightly will degrade the exceptional ground handling this bird is capable of.