The time of year is an obvious concern for Caribbean Storm Tracks. As an experience Caribbean diver, you must have already taken that into account.
Your options become affected and dictated by the weather pattern, as do the room rates.
You say you have been to Roatan. Have you been to both sides West/North and then South? Vast differences (and outside the regular Caribbean Storm Track)
You want "real shipwrecks". I think that would be "non-placed" human screw-up type wrecks. These wrecks, by their very nature, are caused by close-in proximity to land, running aground. This location and event is accompanied by obviously frequent storm-wave action. Actual, real-deal wrecks are very short lived, even most "placed" wrecks are quickly shredded to tatters.
Grenada.
The biggest draw here is the BiancaC wreck, and it still exists as an intact (outside of a 1992 storm damage) wreck because she sank deep at 165fsw and 3mi offshore due to fire. That puts her outside the norm of most actual shipwrecks. The large majority of divers here are from England. The other people on the plane are bird watchers. It is a hump for us North Americans to get to, more cocking around than a direct flight from England.
The best diving on Grenada, nobody does. It is on the far NE coast among the barrier islands. Grenada population and tourist infrastructure is concentrated on the SW tip. The big draw, the cruise ship wreck BiancaC and it's top deck "pool", it is occluded, very deep and has currents. There really is not much to see, but like the Belize Blue Hole, it seems to draw divers like flies to a yellow porch light.
Off the beaten path?
And also out of the hurricane/trop storm potential path?
Tobago. Hard to get to. The North East end is my choice. A lot of British bird watchers, more birders than divers by far. People think they have been in current after their big Cozymall Trip. Mexico current diving was a warm Summer's breeze. Tobago will be the thrill ride you need before dealing with the Galapagos. (No surviving shipwrecks here)
Los Roques VZ (not Margarite) LOTS of real-deal actual SHIPWRECKS that may or may not be visible under swirling sand in shallow waters with current. Hard to get to- Caracas to Gran Roque, charter with an open dory boat operator. Go be Clutch Cargo. Superlative but rustic experience for non-divers, too.
Cattle Boats
How do you define that? Everybody has their own internal picture. Some people reference the DMs attitude, some think only of the actual number of divers- but either of those two "main descriptors" are highly dependent on the guest divers perceptions driven by past experience.
What's a cattle boat, specifically to you?