9C 3004 cassette or Crystalyte H3548 in 20" trike

I am reworking my ICE Sprint (tadpole) trike with a new motor in the rear 20" wheel and trying to decide between the 9C 3004 cassette or the Crystalyte H3548. Which would you suggest and why? I am also interested in other direct drive motors that are between 500W and 1500W. I'm looking for something with decent build quality.

Maybe this could be a good alternative:
http://endless-sphere.com/forums/viewtopic.php?f=30&t=66489

Whichever solution you choose you will love the results! I've got 9C freewheel motors on both a Catrike Road, and an Actionbent recumbent trike, and they are both excellent fun. Just use lots of torque support - 2 opposing arms on both sides of the hub. Cassette would be nice - I'm stuck with Shimano 13T freewheels or 11T DNP freewheels. My alloy frames had to be spread by about 2 mm per side to shoehorn the motors in - that was 13,000 miles ago.

Get the 9C. The crystalyte 35xx's have build problems. The 9C 3004 is also going to be more efficient due to it's thinner laminations.