Hiya Gary,
i could recomend you Motors, ESC and Props untill they come out of your ears... but most of the time or should i say 90 % of the time if the Prop fits under the Hull, then the Motors Diameter should be bigger than the Diameter of the Prop, when testing the Motor and a Maximum Drain on the Amp meter only reads 8 Amps then a 10 Amp ESC will also do... that is the rule of 10
Personaly i use Bühler Motors, which have a very low Maximum Drain round about 0.9 Amps, most of my Motors have 5-8 colectors and a low RPM about 4000-8000 in a Volt range from 6 to 24
the speed controlers that i use are the Rokraft 100's from Robbe, although now a days there not much difference
As for the Prop, of course it has to fit??
a geard, Decoperm will drain a 10 Amp batterie in about 1 hour, if that is enough drive time then by all means use it, but if you go to your scrap heap and take a fan motor from lets say a Ford then your drive time would roughly double, and that would be on driect drive not geard...
hope this has helped a little