Hi
I've lived in various parts of Orihuela Costa for 10 years now, and I also say that La Florida is not the best location if you want to get out and about on foot or bus.
In addition to what others have said about Punta Prima I will point out that there is a very good local bus service into Torrevieja, which is additional to the "inter city" services to Cartagena etc.
Another good option would be somewhere close to La Zenia Boulevard, where there are also lots of facilities, and it's reasonably easy to catch a bus.
You will find that the various areas are not clearly defined - eg we live in Playa Flamenca, but we are just a few minutes walk from the Boulevard, and I have no idea where the dividing line is with La Zenia! So if you've identified any properties of interest, try to get at least the name of the road and then look on Google maps!
btw, just to be nosy - why are you leaving Mazarron?
Cheers
Steve