This is the pump that comes in some of the kits Ding Sheng DS-3500 if you use these spec's you will be on the right track these are only 75W and 3000L/H there are lots of fish tank pumps that will do the job as well the only problem is the hose connection so if you can make an adapter for the hose connection you can have a pump between $12 and $20 https://www.yoycart.com/Product/45300079437/
Check on Ebay as well they are there