What kind of inverts do you want to keep? That will help me to give you an idea of how/where to start. For shrimp you can use either a sponge filter or HOB with a sponge over the intake. Most neocaridina shrimp (cherries, snowballs, yellows, blue pearl etc) do well in a broad range of ph's and temps. I keep mine at about 74. They look best on a darker substrate and enjoy a tank that has some dense planting. The general rule of thumb for them is about 10 shrimp per gallon of water (bioload wise). For caridina species (crystal reds, tigers, dark green, etc) they are more particular about pH and temp. They generally like a ph range of 6.2-6.8 or so. They also enjoy a planted tank adn the same rules for filtration apply, just cover the intake to protect babies. Mystery snails (apple or pomacea bridgesii) are a nice addition to an invert tank. They generally get to about golf-ball sized and need about 2.5 gallons per snail. They are plant safe but require a calcium rich diet to ensure healthy shell growth. They do best in a ph over 7, the higher the better to prevent erosion of their shells. They come in a wide range of colors from purple to magenta to ivory to gold to blue and more. They are sex specific and lay their eggs above the water line in clutches that look similar to clusters of grapes but are a light pink. They have alot of personality as well. Olive nerites are another nice snail for an invert tank. They are exceptional algae eaters but do not breed in freshwater, although they will lay small white eggs that look like pieces of rice. There are common snails as well that can be a nice colorful addition, ramshorns are my favorite. I have red, spotted, and brown. They are hemaphroditic so can readily reproduce with a food source.
Cherry shrimp reproduce very readily adn are a nice colorful shrimp to start with, as are yellow neocaridina. Hope this helps, if you have a particular invert you were interested in, let me know and I can get you links to appropriate information.