What kind of pumps do you run currently? The 15000 seems like a lot to me if the specs on your current tank in your signature are correct. Even if you did 10 times on the return it would be about 1800gph. That 15000 is over 34000gph but would be less depending on the head pressure of the plumbing.
You could probably do a DCP 8000 or even 10000. A little more about your setup would help also and what you are wanting to do. I will agree though you'll want a DCP series as the DCT is the 2nd generation of the Jebao return pumps.
I run a DCT4000 but I bought mine before the DCP came out and it's been running a year flawless but I clean mine every month.