It was recommended to me that those switch kits really don't help much. It's very difficult to discern the difference between switch types based on a single switch. You really need to compare a full row, or half and half between one side and the other.
As far as TKL goes.... you'll need to stick to minimum 75% if you want F keys. Anything below that is more than likely going to be 5 rows max.
Switch choice is really difficult to come up with unless you have access to test keyboards. Basic types are Linear (red / yellow / black), tactile which has a slight bump at the point it activates (brown), or clicky which has an audible noise at the activation point. Once you decide on that, the next step is spring weight.... I find reds way too light and prefer yellows/blacks, but that really comes down to personal preference (SugarJ prefers a much lighter switch than I do).
Those colours are based on standard cherry switches but many other manufacturers use a different colour scheme so you have to work off of style (linear/tactile/clicky) and activation weight/stem travel distance.
