Are you planning on keeping corals? This can make a difference in your decision.
If you get a package, get one much smaller than your tank size. Most packages for 100 gallon tanks would be rediculously high.
I'd go with nassarius (if you have a sandbed), cerith, trochus, and stomatella snails. A couple cleaner shrimp for show. A couple peppermint shrimp are cool too. Avoid the cucumber, but a serpeant/brittle star is nice.
What kind of substrate do you have? If sand bed, then you have to choose if you want sand sifters. I avoid them because I like keeping all the microfauna in my sand.
If you're avoiding crabs, then avoid the conchs for the same reason. No crabs for my tank either by the way.