Removing as many inverts as you can may be the safest route. That would allow you to choose a more direct method of killing the ich such as heat+salt.
I've heard of success with heat only...however this generally requires bumping temp all the way up to around 86-88 F from what I've read. Definitely depends on the heat tolerance of your inhabitants which could also be stressful on the inverts. DO also can become an issue.
I've also seen varying info on meds. Some have dosed malachite green, formalin, etc. with inverts and been safe...some have been ok at eradicating the ich with lower doses. Obviously nothing copper based, even if you remove the inverts since it could potentially leach from objects in the tank later on.
Definitely the best route would be to QT the fish beforehand, observe, and then treat if necessary before introducing them to the tank. Ich could potentially still happen but it will greatly reduce the chance of an outbreak.