You shouldn't go wrong with any of the companies you go with, you just need to ensure they cater to the riding you want to do and the type of area you like.
Morzine and Les Gets are good if you want to be surrounded by kids with big-rigs.
Verbier is great, as is Pila. For the best singletrack head to Les Arcs area, fantastic natural trails and the lift system is one of the best out there for uplifts.
Don't think the Sainte Foy lifts are open in the summer. Verbier lift run a few times a day from memory.
If you want fantastic lift assisted singletrack, xc and DH Les Arcs has it all. The majority of STWers have been with TrailAddiction and keep returning due to the great chalets and fantastic guides. Highly recommended.
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Have fun!!!