The pump is a flo-jet 2.9 gpm and it has plenty of volume. Here is the link to where I purchased. Based on the searches I did this pump was hard to beat at $49.
The hardest part was just figuring out all of the pieces for connections and you could save a few dollars using nylon fittings vs metal. Here are a couple of additional thoughts/comments: I did have some trouble finding the cold water T and the shipping was way more than the part! I could have built my own hot/cold hoses, but I could not do it for the $14 the pre-made hoses cost. Plus the red and blue make it easy to figure out hot and cold adjustments at the Y. It was a lot cheaper than a shower from heatercraft and I like doing projects like this...especially after I find out it works.