This will be a later build for me...maybe over the fall/winter months. I'm just not sure if I'd want to scratch build or get the kit.
If I resided in the US and with the knowledge that for a lot of users they end up building 3 copies of most designs they choose to fly, I would proceed the following way.
Buy a kit from the FT Store as well as a number of FB sheets. I would firstly use the kit as a template and make my first one from the templates. I would also make a second set of templates using the FT kit as a template.
There are my three planes! I would build the first plane from the pieces I cut out using the kit as a template. Doing this I would make mistakes on something which possibly has a few cutting errors and other issues but it cost a few dollars only.
It is this scratch built version I would maiden and learn to fly the plane and trim it on. Chances I would make a number of errors and have a few crashes before I got used to it.
Whilst I am learning to fly, (and crash), the new model, (my scratch version), I would very slowly and carefully complete the build of the FT Kit version and decorate it as I want it to be finally. If I need to replace parts or the complete aircraft because I have damaged the original build I would use the new templates to cut out and build replacement parts to keep the original build flying! When the Kit build is finished i would have 2 models. One for flying on the days when really even the birds don't fly much, and the other for those beautiful bright calm and sunny days that arrive from time to time.
Using such an approach I would not need to struggle with plans, the problem of stuffing the build of the Kit, not having any ability to cut out new pieces as required, and not ever flying the model I know it could have been had I not rushed things a little.
So to answer your dilemma do both!
Have fun!