Coralife Super Skimmer 125 needle wheel

Hello everyone. I am having a heck of a time finding a replacement for my coralife super skimmer 125. I have not used it yet and need it working soon. I bought it used from someone with the understanding that it worked. Well when I got it home the pump did not work. I have found several sights that offer this pump however they are all out of stock. (that kind of puts up some red flags) I purchased from 2 sites and they both contacted me that the pump was out of stock. This was not shown as out of stock on their site. I did find one from someone on ebay but after thinking about it and with all the out of stocks might mean this is a bad pump!! My question to you all is if you think another pump would be better for this. The stock pump generates 500 gph and is a needle wheel. Will any needle wheel pump that can output the same quantity of water work for this. Any suggestions would be greatly appreciated.
Thanks.
John