Hmm... Well, I LOVE Vo5's Shea cashmere! It has protein, and it's pretty moisturizing and has decent slip for how cheap it is!
But I have had a lot of luck with GVPCB and mixing some CNPF with it! Both available at Sally's, and not very expensive at all!
Shea Moisture's products all have protein, too. I like their masque, but I combine it with other things bc I need slip. They also have a restorative conditioner, but again I find it's not slippy or rich enough. I do use it religiously as a LI, tho!
Sally's also has a protein filled treatment by Ion - I think it's called Restorative treatment or something... I can never remember until I see it, and I'm out right now! But it's good, too!