I went summer skiing in France, Switzerland and Italy 3 summers ago and had a blast. Most of the hills are crowded with kids training for downhill and slalom etc and the snow isnt very good, but its still neat to ski in a short sleeve shirt. Although, in the Les Duex Alps (pardon my French... I cant spell French worth shit) it almost seemed like it was winter. It really depends on how high the mountain is and where it is. I've heard of it snowing in the mountains in the summer and making some nice powder.
So yeah, dont expect it to be amazing, but its something every skiier, in my opinion, needs to experience.
Oh, as for your gear question. I'm 100% positive about renting skis/snowboards and boots. I have no idea about gloves, etc.