Like Danno says, missing tooth isn't a big deal on the big ring. Repair the chain unless it's needing replacement, either get a Shimano replacement pin or a quick type link (SRAM is one brand, there are others like KMC). There is a possibility of reusing a pin on a Shimano chain if you want to peen it yourself. You'll need a chain tool to do the repair. If you do want to get chainrings likely you don't need all three at the same time, and if you do, often a new crankset can be a cost effective way to do it. In any case that's a 4-bolt 104/64 bcd (bolt circle diameter) crank and you'd get chainrings with that spec....