If you look around the site, you will find extensive discussions about sizing Mazzei's. What you want is a system with a pump with sufficient head to power water through the injector efficiently, creating a strong vacuum on the CO2 line that will largely dissolve the CO2 and provide some mist. The 3 or 5 series Mazzei's have different venturi throat diameters. The smaller throats coupled with a high head pump do an amazing job of dissolving CO2. The larger throats of the 5 series need a larger throughput to do the same, but if your pump (filter, powerhead) doesn't have high head then a larger throat will allow it to still move lots of water. You'll get mist. If the pump is powerful enough, it will be fairly fine mist--as fine as you get with a good quality diffuser, but more controllable.

So look around the site. Think about how you plan to drive the Mazzei, then worry about getting it plumbed into your system.