Ecotech Marine Powerhead Question

[Octavian]

I'm in the process of upgrading my 29 gallon saltwater tank to 50g tank and was wondering what people would recommend for the powerheads...

1 or 2 Ecotech Marine VorTech MP10 ES Water Pump

or

1 Ecotech Marine VorTech MP40w ES Water Pump

The tank will have sugar fine sand and live rock from my 29g, 2 clowns, 1 lawnmower blenny, a large toadstool, several zoas, kenya tree, brain, frogspawn, pulsating xenia, green star polyps and some ricordia.