Black or Navy Tux? Second what color pocket square are you looking for? If you're going with a black tux, you can stick to a simply plain white pocket square. If you have a Target near you, they sell a pack of 5 from Merona for $5. Another option is a white pocket square with a black accent. Kind of like this
one but instead of blue, black. I actually bought the last white PS from them with the black stitching...I should get it some time in the next couple of days. I don't know when your event is but if you want it, so that you can have that extra pop of the white with black, just let me know, PM me. I'll charge what I paid.
Cufflinks, what's your price range?