So let's say I want a Steam Kumos and the pet I want to turn steam is an Antlephore, Will it turn the Antlephore into a Steam Kumos or will it have a be Kumos to use the Kumos plans?

It can be whatever Pet, as long as you are using the Kumos Schematic it'll turn into a Kumos. My Nautilus was a Hydrus Popoko at the time he turned Steamwork and since I used an Achan Schematic he changed into an Archan as well.

Ah, thank you very much! Steamwork Korra here I come!