You should go and have a look at the UK detailing forums. Snowfoam is much more of a 'thing' with us in the UK and there are literally hundreds of products.
Is snowfoam different to car shampoo?
In practice, regular car shampoos are not anywhere near as effective as dedicated snowfoam products - so stick to a product specifically intended for use in your foam cannon.
What type of snowfoam is best?
pH neutral products are rather ineffective, they aren't useless but won't do much good unless the vehicle has only very light soiling. On the flip side, they are extremely mild and will do little harm to any LSP. They are also mild enough for skin contact - you won't irritate your skin if you use a wash mitt to 'work' the foam.
Basic alkaline (not containing sodium or potassium hydroxide - caustics). These will clean much better but the reality is that a touchless wash will remain difficult unless the level of soiling is relatively moderate. You wouldn't be using one of these products as a normal wash soap because it would have too high a pH for regular skin contact. These can strip some of your LSP at too high a usage level but they are relatively safe. They also will not cause harm to any aluminium or sensitive trims.
Caustic (containing sodium or potassium hydroxide - caustics) products are the most effective cleaners. If you want a touchless wash, these are your best bet. The downside is that they are the extreme form of alkaline product. The pH will be very high so you should definitely not try manually working the foam unless you have gloves on. Caustic products will also be the harshest on your LSP. Another note is that sodium/potassium hydroxide react with both glass and aluminium. At the final contact concentration, the effect will probably be small but with regular use, aluminium finishes will be corroded leading to dulling and glass surfaces will react to form crystalline silicates which give a hazy appearance and cannot be removed chemically (they need mechanical abrasion because they are bonded every bit as strongly as protective coatings).
There is a tendency for the aggressive nature of the final class to be downplayed because caustic based products are particularly cheap for manufacturers to produce. They are superb cleaners but I personally feel their place should be reserved for truckwashing and the cheap $5 car wash guys. As Mike often says, use the least aggressive product necessary to do the job - for most jobs, caustics are simple not required.
If in doubt about the content, check your product data sheets. pH neutral products will list a pH of 6-8, alkaline and caustics will have high pH (typically upwards of 12) and caustics should show either sodium or potassium hydroxide (caustic soda and caustic potash, respectively) in the list of constituents.