Hello,
the interface will be defined by the drop in and by the tailswitch.
The first choice is to select a drop in with or without memory. If it has a memory it will switch on with the last used brightness, if it has been switched off long enough. If You switch it on short after switching it off, it will be in the next mode. If it has no memory it will always switch on in the first mode of the drop in.
you can choose between a forward and a reverse clicky. The reverse clicky switch is nice if You want to change the brightness setting while it is switched on. With a forward clicky it is easier to select the brightness while switching the light on.
My recommendation is to buy both kinds of switches and try out which one is the right one.