We are working on a solar/battery/electric power a seastead.

We have mostly been thinking to use two (for differential thrust) of the 2.5 meter diameter low speed submersible mixers.
Even though we had columns/legs in the water this would move us around slowly like 1 MPH and make careful use of eddie currents.  
However, in some new seastead designs we have replaced the columns/legs going into the water with wing shapes.
These more hydrodynamics designs may be able to go like 3 MPH.  

Also, having lots of little thrusters could let us put one on each side of each wing
and use differential thrust to rotate each wing, increasing seastead stability.
With 4 legs/wing/floats and 2 thrusters on each that comes to 8 total thrusters.

So now I am interested in smaller thrusters.

I like the "RIM Drive" used in the Yamaha HARMO.  It provides a 227 lbs of thrust from 3.7 kw which is
better bollard thrust per kw than others I have found.  I think price is like $3,500 which is not bad.
The RIM Drives should last really well and have low vibration.
We expect to get parts for the Seastead in China. 
Please try to find RIM drives with over 100 lbs of thrust made in China.
Some Chinese web pages use RIM when they are not really RIM drives, so be careful to check.
Just having a duct around a propeller does not make it a RIM drive.  
In a real RIM Drive the magnets of the motor are in the rim around the propeller.

Thrust, power draw, weight, efficiency, and also price are important.  

It would love to have a graph for RIM drives showing thrust different speeds though the water.
It also seems as the speed gets close to the point where the drive is not providing any thrust that
the power draw must be going down.  Can you make a graph showing the power draw at different speeds?
Can you find something like that or from theory estimate such graphs?

Please look for sources of possible alternatives to "low speed submersible mixers", in particular from lower cost Chinese,
and with some focus on RIM drives which I think look promising.

Please make a table with the following columns to compare above and what you find:

Type (RIM, Submersible mixer, ducted, etc),     Lbs Thrust,   Watts,    lbs/kw,  $ price, $/lbs-thrust,   URL