It really depends on whether you plan to trailer this boat or plop it in once a year and pull it out at the end of the year. Most of the O'days in our area came with a Load-Rite roller trailer and they discontinued this model trailer, but the O'Days hulls are strong enough to take this type of trailer. If you plan on mooring or slipping your boat, you can go for a flat bunk trailer. I bought a Long Mfg tandem aluminum trailer of Walmsley Marine and I love this trailer. You may be able to get away with a single axle if you don't plan on trailering too far with it, but you should try to get a trailer that is long enough to go in deeper without having to get your towing vehicle swamped. You may need to buy extra long extensions for your bunks. He has these in stock or he can get them. He can look up your boat on his PC and come up with a trailer that's suitable. Also, he can fix you up with a Long Roller trailer.
Joe