You can rent only skis, snowboards or not, or the choice is very limited. But the skis are good, new, track and station wagons, all sizes. It is better to come to the resorts of Mestia with your own equipment and equipment. Choosing equipment and equipment on site can be a challenge.
There is no information about the availability of an instructor school in the resorts of Mestia. There is a high probability that you will not be able to find a good instructor. It would be quite reasonable to come to the resort with your instructor.