As I have mentioned before, I do not own a lot of gear. I use a Canon 6D with a 35mm 2.0 and an 85mm 1.8. I used to own a 20-35 but sold it since I did not use it much.
If I need specific lenses or equipment for a job, I tipically rent. There are a couple of companies you can use. These include the big camera store out of New York. The one I like the most, is: lensrentals.com They are very easy to do business with. Have lots of stock and more importantly, different brands.
Right now, they are offering a sale on rentals this summer. The coupon code is for 20% off any rental. You can even purchase any of the gear you use. They test and maintain their inventory very well. I highly recommend them.