You basically have 2 choices.
First, portability is no longer available, so you must get the RV plan, unless you only ever plan to use it at your marina, and not use it in any anchorage.
Your choice is of the
antenna. You can get the regular rectangular antenna which is smaller, cheaper, and works well. HOWEVER, it is not permitted to be used in motion, even though it works while moving. Many use it in motion, even though they are not supposed to.
Or, you can get the in-motion RV antenna, which is quite a bit more expensive, larger, and is permitted to use while moving.