I really like the Superior Choice....my ferrets have done really well on it. Totally Ferret and SC run about the same, nutritionally speaking. The only difference is the price. TF is super expensive, especially for multi-ferret households. SC is a great food all by itself, so don't feel pressured to feed a mix if you don't want to
I've always fed a mix over the 9 or so years that I've had ferrets.
Over the years I've used all different foods
These are what I would consider high quality ferret foods
Marshalls(good food, but makes stinky poops due to the fish content)
I've heard the Path Valley brand is ok, too, but I've never used it and don't know many people that do.
Maxximum Nutrition(purple bag...Walmart's brand of cat food)
Premium Edge Kitten(which is "rumored" to be the Path Valley diet formula)
I also used Pro Plan Kitten Chicken and Rice but that was years ago
Iams(or is it Eukanuba?) is also ok to use
Can't think of any others offhand...