Lots of good tips, but no one mentioned the tubing you would possibly be using, which is Quantum tube on the PML kits. As mentioned, there are certain instances to use glassing, most of which are not absolutely necessary unless you go supersonic.
You forgot to mention where you live...if it's cold, etc... This will impact what you do. In warmer climates, the PML kit would be fine, but in colder climates, I recommend you glass the Quantum fin can area only. Quantum tube becomes brittle in cold weather and glassing the fins adds a ton of strength to the rear end that will be hitting the ground. On cold days, I have seen Quantum shatter. Also, the piston ejection will need to be sanded to fit on cold weather as the chamber does shrink and the piston ejection becomes tight. I always fit my piston for the coldest day I plan on flying and it works well for everything!
Tip: on PML kits, get a second coupler with the kit, cut it to the length of the piston, then split it and fit it inside the piston to "Double-Wall" the piston assembly. this will prevent cracks from too much ejection charge; I have seen pistons litterally blown apart from the inside out from too heavy an ejection charge, while the model faired fine. It will give you much more material for strength, as sanding to fit may make the outer piston a bit thin, so adding another layer inside gives you your thickness back. A second thing you can do...make the piston detachable with a quick link. this way you can use the piston in the summer and stock deployment with a nomex cloth in the winter.
Don't let some of these tips on PML change you over to BSD only....PML has some of the best kits on the market imho, and I and many others here own several of them. The Quantum tube that PML uses for body tubes is smooth as glass, is made from a 1/16" thick plastic polymer and paints like a dream! It's very strong and very flexible...good stuff. Also, the piston ejection works very well if tuned in...a great concept and design.
Keep us up to date on your progress and pics...we need pics!