I don't think electric is ready
But looking at the "KIT" it is really NOT ready you have to come up with your own gear box , The control looks very small to handle 100 to 200 amps
I work with all types of AC and DC electric motors forklifts to machines and the motor looks way to small to replace a 10 HP diesel
That site an many other sites have a wide range of motors and controllers, you can customize them at your will, and as LiFePO4 batteries (same type that's going in the Volt and other electric and hybrids in the pipeline) come down in price, this becomes a viable alternative. I've been researching this quite a bit for another project of mine (electric locost, google it) and have figured out that for a 10,000lb boat something like 15kw is needed, you can get by with the 8.5kw kit, plus it has regen and has been able to put up to 4ah back into the battery bank just using the spinning prop. But watch the lithium iron battery prices carefully, once they begin to drop, not only is it cheaper than a new diesel engine, you can make a relatively light bank that can store a great deal of power. With a 600ah battery bank on say this system here Thunderstruck Motors - D&D Motor Systems. Seperately Excited Motor/Controller packages for 24-48V or 60-84V ranges.
at 72v you are looking at well under 200 amp draw to push a 27-30 foot boat to 5kts, a Catalina 27 was converted to a 48v system and they were getting a draw of 125amps at 5 kts. They were getting 10 hours of run time at 3-4kts, and 2 hours at full throttle. That is not bad at all.