I'm pretty open to either lots of tech or no tech, and I'd say I lean more towards wanting more party customization.
I'm leaning more towards either 4 or 5 right now, as I've enjoyed Square's SNES offerings a great deal so far.
I'm not a huge fan of FF4 myself (only due to having played it a billion times and sort of expanded from there) but it's a very good game to see the first time Final Fantasy really found its footing. It's a very seminal game, and for a console game from 1991 it's got a surprisingly deep/fleshed out plot with lots of themes that resonate well with people and became mainstays of the entire franchise. Love, sacrifice, honor, all that good stuff.
As far as party customization though, it has exactly 0. It's very much a story-first kind of game, and you have no control over which characters you have in your party, and you can't edit them aside from equipment. That also means that every fight is sort of designed around your party at all times though, so it's not all bad.
Final Fantasy 5 is very unique in that it has a story that is really light AND light-hearted compared to just about every other FF game. And it's the one that really defined the Job system, which lets you change classes on all characters and combine various abilities from different jobs once you get experience with them.
It having a light-hearted story doesn't mean it lacks impactful or emotional moments however, but it's a "different" FF in that it kind of feels like an episodic adventure where you adventure around the world solving one quest at a time which slowly inches you towards the greater plot.
