With an EGO-T you have plenty of options:
1) anything with a 510 connection will fit on your Ego, mechanically and electrically.
Atomizers, Cartomizers, tanks, clearomizers, the lot. will screw in and allow you to vape. May not look pretty using a cartomizer w/o the cone after getting used to the smooth lines of your CE4, but will get the job done. That being said:
2) The Vivi mini and the ego tanks are designed to mate to your ego seamlessly, like they were made for each other. For the best look, these are a good option.
3) There are several different adapters you can attach to your ego battery which will "dress up" your connection to bigger tanks like the Vivi Nova. The "original" Vision clearomizers (the ones with the opaque white plastic and tank looking mouthpiece) look pretty good on an ego with one of these adapters. This only addresses the "look" of your PV, the functionality will be unchanged (more or less, some adapters change the 'airyness' of the draw).
A selection can be found at nearly any
vaping hardware website, usually under "PV parts and accessories" MadVapes has a few good pics, only bring them up due to familiarity.
I personally use different types of carto/clearos depending on the flavor I'm vaping. Clearomizers and clearo-tanks like the vivi nova have a more "clean" flavor, which works better for me with fruit flavors and other light juices. I reserve cartos/tanks for darker, more savory juices like chocolate, coffee, etc.
You are off to a good start with the ego battery, have fun!
