Saw this a bit back, looks like a decent program written by a strong guy. If you want to up the pace and get a good conditioning aspect, you can do sets of pushups, burpees, or just Ab stuff like leg raises or v crunches between your sets.
If you want a bench and have a couple bucks and a couple tools, you can build this bench:
I built it a while back and instead of the vinyl and foam I just used two mats from Lowe’s, the puzzle-style kind that interlock.
But, coolers, tables, etc. are a good, easy way to have a bench around. Besides that though, you don’t need a bench at all, so enjoy!