For best levelling experience?

Good evening ladies and gents!
I'm coming back for a nostalgic trip and had a few questions.
I'm planning on playing the game without leeching or hp washing. Just mostly focusing on the leveling portion of the game.
What I want to know is what do you think, in your opinion, is probably a decent class given that criteria?

Also, for anyone else that decided to not start off with a mage to sell leech, were you able to upgrade your gear with the mesos you farmed or how was your experience?

I probably won't make it to endgame, hell, might not even make it to 4th job! I just want the therapeutic feeling of grinding mobs with my own skills and gear earned by the same character.

So yeah... I guess that's it.

Thank you!