There is a huge difference between the kits. The ZZP kit takes the smaller M90 housing (from the stock blower) then takes the longer rotors from the M112 and puts them into the stock M90 housing using spacers. So ZZP's is really just an M90 with M112 rotors.
On the other hand Intense's MP112 conversion allows you to remove your stock M90 and completely replace it with the MP112. Although it is more labor intensive, and more costly, you will make more power with this setup.