There are plenty out there, is there anything more specific that you are looking for?
From my experience (not much) I would recommend the Markbass Super Booster, it emulates Markbass amps and I think from my ears that it does it pretty well.
The Sansamp BDDI does a very good job emulating an SVT!
Other than those 2 pedals I can't say much more...=\
Oh! EBS Valvedrive (my favorite) is a pretty cool preamp/eq pedal IMO, warms things up, but it is a tad bit pricey and big.
The Source Audio is definitely the bomb, but I wouldn't discard the idea of Boss. I ran a Boss EQ for years, often time kicking it in for a solo or to change up my tone... they're built like brick sh**houses.
Not really looking for dist or overdrive. Mainly to boost a passive bass signal live, be good to have a DI as well. Tech 21 and markbass look good, as well as the EBS. I'll go and play a bunch of them.
Pedal Breeders Big Board Club #21 The Fender Jazz Bass Club #1103 The Ibanez Club #1143 Gallien Kreuger Official Club # 1021 Gordo Club (Mike Gordon) #40
Go with the Boss GEB-7. Most essential pedal I own. Every time someone asks me what it does the only way I know how to explain it is say "it literally brings my rig to life" give it a try. It gives a killer boost and will take care of any tone alterations!