I suppose a lot of it has to do with where you plan to cruise in your Maramu. Space is a little more limited on the Maramu than on the SM and larger Amels. We knew that we were going to cross a couple of oceans and did not want to have it on deck during those crossings (much less have something hanging from davits off the stern). We selected a four man dinghy with an inflatable floor. The dinghy could be deflated, folded and stowed in one of the forward bow holds. Eventually the inflatable floor failed (holes that could not be repaired) and we had a rigid plywood floor fabricated. It's a bitch to install, but once in it works great as the bladder to form a hull wedge still inflates. With the 9.8 Tohatsu I can quickly get up to plane with two aboard and when we are gunkholing from anchorage to anchorage, we lift the dinghy and engine together onto the foredeck, protecting the deck from the engine lower unit with beach wheels extended.
If I wasn't going to cross oceans, I would go with one of the many hard bottom options but keep it short to fit on the foredeck or the aft deck.