You are in a very good position since you already own a bass. Take your time and play as many basses as you can until you find one you really like. If you buy used, you can get more bang for your buck.
The worst thing you can do is run to a store and buy something on a whim. If you decide to purchase new, try not to buy something the first time out.
In other words, play some guitars (make sure to us the same amp/same settings), make a note of the ones you really liked, go home and let everything soak in, then go back to the store after a few days and see if you still like your choices from before (again, using the same amp and settings). If so, narrow down your choices, then get the one you liked, if not, simply keep looking.
Again, since you already own a bass you are in a position to take your sweet time.
If it helps any, I recently purchased a used Geddy Lee Jazz Bass (CIJ), I would put it up against any MIM or MIA Jazz bass. Let's face it, the Japanese have been in the manufacturing business for a long time. Products they build are world class.