Lu,

If you're interested in trying a fountain pen and you prefer bold lines, I would recommend looking up the Pilot Varsity. Get one with a medium or bold nib.

The Pilot Varsity is a disposable fountain pen and it's in the same price range as some of the good normal pens. It's a low-risk way to start since it's self-contained (you don't have to buy ink or anything) and it's disposable (so you don't need to worry that you're throwing away a fancy pen if it doesn't work out for you).

Two other small points if you choose to go that way:

1) Use good paper. Wet pens like fountain pens bleed through cheap paper really easily.

2) It will take some time to learn how to un-clench your hand if you're moving from a ballpoint to a fountain pen. You should experiment with how little pressure it takes to write using one. After a few weeks you adapt to it though.

I'm at a point where I can write thousands of words a day without my wrist feeling any pain (it def. feels fatigued tho).

If you don't try the Pilot Varsity you can just as easily try a good ball-point that uses wet ink or gel ink. Pilot comes through in that regard, too; a Pilot Precise V5 with a medium nib is a good writer.