I am partial to the old twin-coil switch machines (Tenshodo, PFM, etc.), too. That said, the easiest machines to install on Gargraves are probably the ones from Z-Stuff. They also have quick "snap" action, and can be thrown by hand as well. The twin-coil machines are large enough that you will probably want to hide them under the table, and then you lose the ability to throw them manually; the Z-Stuff machines draw less attention to themselves. However, they are not 100% reliable. We have maybe a dozen of the Z-1000 switch machines in service. My experience is that the ones that work are absolutely consistent, but every so often you get a lemon. Those, it is best to just replace.
For ultimate reliability, there is the manual ground throw by Caboose Industries. The only problem with this is that, if the train derails, you can't blame it on the machine 
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I should add my (slight) experience with Fastrack. I only have switches in O-36, and they are all manual. I have been very happy with them. They are noisy. But trains from prewar through the present run through them well, and they have a nice spring-loaded "non derail" feature that allows the wheel flanges to force the points over if you approach it from the wrong direction.
