I was asked by a co-worker to do some dog/cat portraits for a local rescue group. There may also be some shots of owners with their adopted pets. I don't have any experience doing portraits so I am hoping to get some advice here regarding my equipment. I shoot a lot of product shots for my wife's online shop so I already have a modest studio setup. For this rescue group shoot we will shoot at a location to be determined (not at my house). My equipment is in my sig - what's not listed is a couple of light stands and a Cheetah Qbox 24. Tomorrow we have another 580EXII arriving (my wife wanted one too). So I'll have two flashes to use and one softbox. Since I have an extra light stand, I don't mind buying a cheap umbrella or something. I can also use my wife's 7D if that helps for remotely controlling the flashes.
Any advice on what kind of cheap diffuser/reflector to use for the second flash (if I need one at all)? I'd be willing to spend no more than $100. I'll keep reading through this section of the board in the meantime.
Thanks!
-Tim
jk. You just have to find a way to blend them together and get them set up. Having them sit on the ground or low to the ground at the same height of the dog/cats will help or if it's a smaller animal have them being held a do a tight shot of the owner/pet looking at each other or something. 

