I have some experience that I think is relevant. I play both electric bass and upright bass. I have two upright basses - a 3/4 scale Shen hybrid (DB) and an Eminence EUB. I play in a band where I use both the electric bass (probably 50-75% of tunes, depending on the show) and the Eminence EUB. Mostly pizzicato but a few tunes with the bow. So here's my take on it.
The Eminence EUB is one of only a few EUBs that can get close to a DB in feel and sound. I use similar strings (Spiro solos), a DB pickup (Realist lifeline) and it has the same scale (41") as my DB. However - and this is the big factor - I am already quite adept at playing DB with a bow, so its not hard for me to get the sound that I want out of the EUB. Yes, the DB sounds better on its own and in my other band (guitar/bass/drums latin trio) its all that I use.. But In a fairly loud band, its a small tradeoff as the EUB sounds damn good, can get loud without feedback, and is easy to transport when I already have 1 or 2 speaker cabs, an electric bass, and other stuff in my car.
The more important factor is that as you describe yourself as having rudimentary notational skill, it will realistically take you a long time and lots of hours of practice to become adept on the EUB or DB, even more so with a bow. Its not that hard to go from guitar to electric bass - longer scale, bigger strings, different technique, etc but fundamentally not all that different. But upright bass, whether EUB or DB, is a completely different animal, and guitar skills do not translate at all to DB.
My suggestion is 1) find a way to rent or borrow a DB (doesn't matter if its a decent EUB or a DB) and maybe with a few lessons, see if its a realistic goal, and 2) if you decide that it is, focus on electric bass guitar for the foreseeable future with the community band while you woodshed at home for 6-12 months to get your chops together on upright bass.
Bottom line - there are a few EUBs that come really close to what you can do with a DB, and a bunch of them that sound closer to a fretless electric bass. But in my experience, its easier to make an EUB work if you already have some experience with DB and know what kind of sound you are trying to get from it. What you are describing can be done, but its likely to be more work than you imagine. Worth it in my opinion, but not an easy instrument to get proficient on.