"I've played FF Tactics A2, and enjoyed it very much. I'm assuming the first FF Tactics is more of the same (a good thing)?"
I find that they're very different from one another. While I enjoyed FFT Advance, it's nothing in comparison to the original. You really should do yourself the favour.
I can understand what you mean by the GBA Fire Emblems, they do feel different. Like you, I started with the GC/Wii ones and am used to it having voices and having a certainly level of epicness (for lack of a better word) to them that the GBA ones seem to lack. That being said, I still very much enjoyed them but not near as much as the GC/Wii ones.