Thanks for the replies ILENGINE.
I think I'm going to go for it and go with the cheaper engine. I'm a little worried about ordering an engine from a company off the internet, but I just can't afford what the shop wants to charge me for ordering the engine and installing it. Although I am a Blackhawk helicopter engine mechanic, I have never swapped a lawnmower engine. (believe me- turbine engines are TOTALLY different than small gas engines) But, I'm pretty sure I can handle it.
Again, thanks for all the advice