RE: Sig LT40 or GP PT40 for first build in ten years?
I never built a PT 40 but I built a PT 20 way back in the day. The instructions were very good especially for a noob however, the quality of the wood was pretty poor. Not too long ago I bought an OS .30 FS with the intention of building another one and after having more building experiance under my belt since then, I ended up throwing the kit away. It was the worst box of overweight and twisted sticks I ever saw. How this relates to the 40 size, I don't know. Maybe it's better.
I built a Kadet LT 40 about 10 years ago and it sold me on Sig kits. Built a few Sig kits since then and I stick with them.
My vote would be for the LT40 or the LT25 which is on my bench now.