For a first timer the Kibler Colonial is the best choice. I think all the drilling and tapping is now done by Kibler. Ask Katherine when you place the order. Kibler is making high quality locks using CNC machines; this is a huge plus. The wood will fit the metal as is or a little better with very slight tuning.
Track and others are parts sets that can be made into a rifle by a skilled builder. They are not for beginners. I prefer to work from a plank over the precarve stocks supplied in these "builders kits". Most of the time these stocks are messed up. "Un-messing" them is frustrating and time consuming. Understand that if you cut on the the wood you can not return it, even if defective to the point of being unusable. I have gotten burned on that. Sometimes you don't figure out it is no good until you are well into it. Planning out 10 steps and seeing the problems takes experience. Since it is round it is more difficult to have references to keep everything straight and plumb.
You will need to do lots of critical metal work too. That takes tools and skills. The locks supplied on the builders kits are often pretty bad. They often consist of as cast parts assembled with no particular care or fitting. Many of the are just plain junk. I normally have to do lots of rebuilding to make a decent lock of them. This includes new plates, tumblers and screws. I consider the locks from the big two lock supplies as kits from which I may be able to make a decent lock.
I never did a Chambers, I understand that they are somewhere between the parts sets and Kibler. I have done four Kiblers'. They get my highest praises.
