I'm working on a personal project photographing guys that work in convenience stores in NYC. I had initially done this using my 35mm digital but want to reshoot using my newly acquired Sinar f2 (woohoo!). Its important that everything in the shot be in focus so I think I need to use a flash to increase my DOF. Any thoughts on how to set this up? I've attached an older image as reference. I'm going to use a 90mm lens to capture the space around the subject as these stores tend to be very small and I have a canon 430ex flash that probably needs a softbox on it... not sure.

I appreciate any advice.