Effectiveness of various methods aside, there is also the issue of what is fun. If you can meet your cycling goals pursuing a regimen you find more enjoyable, there's no point in torturing yourself just to get a little extra speed/endurance.

^ Truth.

I have a TACX Fortius system where I can ride up mountains etc however personally I feel it is still no where the real thing I still die on real mountains or even less I too have no steep inclines where I live in Royal Berkshire UK

Living in Miami there have got to be some Computrainer or other type virtual reality trainer studios. There are two approaches.

A group session is probably going to be designed to maximize your lactate threshold, which is the approach that will give you the maximum fitness gain for the limited time that most of us have to train. It might be possible to do an individual program focusing on hill climbing training while in a group session but not likely. They will probably utilize the Computrainer as a power meter and not riding courses. I guess it is possible you could find a group focusing on hill climbing but like you have already observed that is not going to be the focus for Florida riders seeking training. An individual training session might be your only option.

You can do climbing training on a simple trainer by elevating the front wheel and using the big ring and the smallest cassette gear. The problem is that while using a higher gear and lower cadence, you cannot simulate the higher cadence of a lower gear. Therefore will be focusing more on strength than would be ideal.