The first question is why did it threw a rod and punch a hole in the housing? Yes you can replace a rod and patch the hole but will the repair job last? You can only know this by taking it apart to see what happen.
Your best option would be to find a good used engine on Craigslist.
I suspect no or low oil lead to the failure. Was the machine used on a hilly lot? Operating the machine at an angle would not be good either, as this engine doesn't have a pressurized oil system (as far as I can tell from my Intertec repair manual).
Lots of luck there but who knows, more likely to find a used mower on craigslist. Check out E bay for a used engine. Just because you have a hole in the engine case doesn't make it junk. Take it apart and find out why. Also you might be able to find a short block. I don't know your mechanic skills or equipment so if you have none you will be much better off with a nice new complete mower.