Kinda weird for me as I played fretless exclusively for like ten years then there was this fretted P-bass at work that I just couldn't put down! I now find it soooooo easy to play fretted bass and I found I missed chords so much that I dug out my Jonas Hellborg chord book! I really think that the touch I developed on the fretless has improved my fretted playing immensely. Get 1- play it alot. Don't sell your fretted bass. Oh I wonder who ended up with my gorgeous Modulus fretted Q5. It really is no big deal to transition to fretless-remember millions of tiny kids pick up the violin every year and the fact that it has no frets is never ever even mentioned. If little snotnosed rugrats can do it you can too. Keep in mind that basses with no lines are not without side position markers and even with lines there will be a period when things sound ugly (heck they still do 10+ years into it!) but the fun factor will out way any and all of that if you apply some thought and effort. Also an instructor may not be out of line if you're not so much a self starter.
I'm in Streetsboro, just SW. Are you going with lines, or are you diving in head first. Me? I need lines

In a good way....