I would sugesst watching this video and the couple others on the chris tarry website regarding pedals
http://christarrylessons.com/the-best-bass-pedal/
The pedal I use the most is the TU-3. for tuning (obviously) but also for the mute function.
another pedal I use a lot is the tonebone bassbone. for any one who needs a DI and plays two basses on gigs it is great. I don't used the boost/drive very often and the need for a odd cord for the FX loop is a poor design.
to get a synth bass sound I use the an octave and an over dive pedal, so I would recommend trying to nail down those before venturing off to synthy pedals.
visit your local music stores and ask what they sell the most of and if they would be interested in buying your pedals to sell. Try locally owned stores more so then chains