I don't care for the type of reverb they're using on the rockabilly guitars. I'd just as soon add my own tape echo. I can't figure out how to remove the effects and record direct in dry, although some of the styles say that I can do just that.
For RTs in general, you can turn off the reverb by unchecking the "allow reverb" box under realtracks preferences in the RT drop down dialogue.
For DI recorded guitars, you can turn off the Amplitube presets (or you can turn off effects in general) by checking the plugins slots for the tracks in question.
If you're not sure if a RealTrack has a Direct Input version, check the "Direct Input" column in the RealTracks Picker. If there's a Y in that column, then it's available.
Looks like all but one of the rockabilly guitars have this feature, so the above suggestions should definitely work in this case.