I dive sidemount all over the Caribbean. Belize, St Lucia, St Maarten, St Thomas, St Croix, St Kitts, Antigua, Barbados, Puerto Rico, Mona Island, The Bahamas. All the dive ops were quite willing to rent me 2 tanks per dive.
Prior to doing sidemount on trips, I did quite a bit of practice diving with 2 right-hand yoke-only valve AL80's. I have my own yoke to din adapters. It's not the dive crew that needs to know how to handle your equipment. You do.
As for boat entry, you need to work out what is effective for you. Fortunately for myself, I can climb a boat ladder with a pair of tanks, even in cold water - in excess of 100lbs of gear.
You also need to work out how you will get from your gear station to the entry and back again carrying everything. I find it easier to don fins in the water so I'm not trying to walk wearing them on deck while overloaded.
It is very important to communicate before the dive that for a two-tank dive, you will be renting FOUR tanks. Also communicate to the dive crew that you wish to rig your tanks early. And between dives, no snacks or drinks before re-rigging. If you get delayed in getting ready for the dive, you may well have to sit out the dive rather than make everyone wait for you.