All the above advice is great. I have used Ed Hamilton with great results. I have also gone it alone with Morring and Sundsail and Conch.
Like others before me 34 feet is ok but can potentially be a rougher ride in the trades with 6 foot seas the norm in the Drake Channel late in the day. The extra HP in the engine from the larger boats also can be an advantage,
We have tried different boats as this was a test for us to see what our next boat may be. It actually eliminated every boat we were on. While we like the cruising amenities the charters provide such as the broad swim platforms aft and the huge galleys, it does not fit with the blue water sailing we intend to do inj the future.
If you can charter from St Vincint to Grenada the second time you charter. BVI is the best for your first time as the sails are mostly line of sight.