There are a lot of discussions on this MTGSalv Niv primer that will help you tremendously focus your deck. Non-infinite and infinite discussions and Rowan, the author of the primer, goes into great deal about card choices and strategy. If you needed some help to focus your deck, this will be a great start for Niv-Mizzet.
Mind you his deck isn't budget friendly, but there are a lot of affordable options available.
Thanks for the help/recommendation! Will be checking out the guide now.