There is a lot of good info out to explain this ignition switch deal....start at http://www.wildharerc.com/downloads/...%20engines.pdf ,
Tom has put a great "getting started" article in there that is accurate and can be trusted.

First, however, the reason to locate the ignition switch forward is that usually forward moves the switch and it's leads further away from the Receiver and it's wiring. Important to try and keep 12" minimums if you are using non-PCM 72Mhz radios. If using 2.4, doesn't matter so much. (Not supposed to matter at all, and that's been my experience running Spektrum/JR stuff). Ignition wiring produces electrical "noise", which 72Mhz FM can pick up and start twitching controls.

Second, a "remote Kill switch" is strongly advised for several reasons, but not because the gasser won't quit when the throttle butterfly plate is closed. A properly-adjusted gasser WILL die when the throttle plate closes completely. If it does not, there is a problem with that engine carburetor or it's adjustments. However - throttle servos in gassers get more exposure to vibrations transmitted to the gear train. This can create undue failure of the gear train, the servo mounting, or electronics failure of the throttle servo. So, the "fix" is to use some device that disconnects the electrical power from the module. Most use a specially-designed electronic switch that plugs into an extra channel in the RX so the radio link from the TX can kill the engine, regardless of the throttle servo or linkage condition. Strongly recommended my many.

Third, to answer your original question - any good quality "standard" radio-type switch can be used on a gasser with a modern module. Since you'll use a rechargeable ignition battery, probably a good idea to consider the charging jack/wiring of the switch to make your install easier. Most use HD switches with integrated charging jacks.