Best way to keep Moto apps but have a nice custom ROM

Hey guys,

I really do enjoy having the Moto app around, specially for voice commands, since I have a ton of tasker stuff on my phone.
I wish I could find a good way to keep the Moto app and still be able to use custom ROMs.

Is that possible?
If so, how?

Do you do that?
If so, how did you do it?

Every input is apreciated.
Thank you.