I use a TS-2 at home and we use a custom made job (Kestrel I think) at work. Just about every type of spoke Key APART from the Park Metal Multi.
VAR dishing gauge is superb, Minoura are only suitable for home use.
My personal fave's spoke keys are the yellow Pro Spokey and black Park SW-0, SW-2 gets a lot of use also as does the Red Spokey.
I do a lot of truing and building hence I have just about everything apart from a tension meter, but will be adding one some time, a spoke threader is also useful, as is a DT-3 and small adjustable.
Average daily wheels trued is around 14, sometimes twice as much, sometimes none.
Wheel building is a lot less these days, but only due to the department and job position I have.
I used to have personal charts for spoke length, used to find Mavic and DT to be out at times so was always good to keep manual records, but I took time off and all my years of notes went missing. I still find the basic DT/Mavic and such online charts reasonable though, particularly when it comes down to a quick build with stock spoke lengths.
If you want to get into building wheels, my own recommendations are even before buying a book, take an old wheel, look at it, and strip and rebuild it (use your bike frame before spending money on jigs n such), use another wheel to compare your spoke lacing and work, and practice at your leisure, if you like this get a reputable book and if you want to build a pair of wheels for yourself start with good solid popular components.
Before spending money work out how often you will build wheels, or true them with any equipment you buy. My TS-2 has paid for itself with the amount of wheels I have built at home, it now resides in my loft and hardly gets used. The custom job has built and trued more wheels than I can ever remember in it's 15 years or so of service.
If you only have one or two pairs of wheels, and are only interested in building one set for yourself, I think it is pretty expensive unless a LBS will let you use their workshop, therefore for the majority of people having them built by a shop is a safer bet with some guarantee on the work carried out.
My own simple rule is 32h 3X and for the last number of years it's all I have been asked for thankfully, its simple, bullet proof and all that most will ever require.
28h and 36 hole are acceptable as can 2X be, but radials, snow flake and other fancy pants builds are a waste, and some others such as 4X and such variables are dependent on the bike and its age and use.
Steve