Custom Products has made a clamping feedneck that is avaiable in the ION threading needed for the Invert Mini.  It is available in several colors so you should be able to find one to match your paintball gun.

The following is from the Custom Products webpage:

We've taken the perfect amount of metal out of the feedneck to give you a neck that is STRONG and LIGHTWEIGHT. This feedneck will not break and to prove it, we've backed it with the CP Lifetime Warranty.

Designed to handle the toughest playing conditions.