lowrider57,
The CM footers under the conditioner are keepers. Yes, they cost more than others but once you have them they will support and improve any future upgraded conditioners.
Now, with that being stated, I have owned both the combo you describe and I am sorry to say that the Niagara 7000 is in a different league from the Core products.
So, probably better to get the Niagara before spending money on the footers.
ozzy