Best bet if you are serious would be to talk to your engine builder, they will be taking your money and covering your warranty, and they will want a happy customer to spread the word for them. Definitions of ports can vary as well, what one man calls a big bridge is a small J, some people will say if its bigger than a big bridge, its just a monster and there is no definition of J port.
As for what is a bridge, a J or a monster, different people have different views because they are all variations of a bridge. Many years ago there was quite a long thread that got onto the topic of port naming. The general agreed definitions that most people were happy with were:
Bridgeport - has a bridge to support the corner seals, but only goes as far as the edge of the rotor housing, without the need to chamfer the housings.
J port - bigger version of the BP, and goes out past the edge of the rotor housing, but only to the inner edge of the inner water seal so it does not compromise sealing integrity, requires a chamfer on the rotor housings to utilise the extra surface area.
Monster port - biggest possible side porting style, requires cutting of the inner water seal and therefore compromises the water sealing integrity of the engine and is likely to lose water into the combustion chamber sooner rather than later. The previous linked picture indicating a J port is what people were referring to as a monster port.
As I said this was a while ago, but alot of the regular users before the young rotor groupies turned up
it seems these days what alot of people are calling bridges are more to our definition of a J, and not many people build engines further out that require cutting water seals, mainly because street cars are usually turbo, and most racing classes outlaw cutting the bridged port further than the inner water seal.
As further evidence of the J not going past water seals, the engine in my 1300 is labelled as a J and built by a workshop, and it has never had a water loss issue for all the years I have had it.