Another satisfied Lensrentals.com customer here. They have a large inventory, dependable delivery and their customer service is outstanding. I'd recommend them without hesitation or reservation.
Here is a link to their resellerratings.com rating and you can read the reviews for yourself
I've rented from LensProToGo several times and always been impressed by the service. One time I even had a lens broken during shipment (elements came loose) and the replacement was smooth and easy (none of the finger pointing game that I had feared). I recommend them completely!