For a couple of those plants, more light would be appropriate, but along with that is going to come the need to dose CO2 and a myriad of fertilizers. The cabomba in particular would benefit from even a 4XT5HO setup, rather than the 4XT8 setup, which would only get you to a little over 2WPG.
Personally, if I was trying to achieve medium or high light over a 55, I would not go with T8. The PAR gains from a T5HO are just too well documented.