Hello Minou,
sorry to say that i do not know what Radio gear is allowed to be used in the USA..!
but if 72 mhz or 40 Mhz is allowed then either would be suitable, of course you can use the newer 2.4ghz sets
a case of personal choice and what you already have to hand..
the advantage of lipo's they are lighter, so you could go for a higher ampers for a longer driving on the pond time..
ESC is also a personal choice thing, a rule of thumb, make sure that the amps drawn from the motor that the ESC can cope with it..
it also comes down to weather brushed or brushles motors will be used..
recomendation for the kit are here:
U.S.S. KIDD
motor: KONDOR 2
coupling: 2.3 /M4 EXL nycrome x 2
ESC: 2 x 10amp
prop 162-13 + 14
bat 2 x 6v
https://www.deansmarine.co.uk/index.php?topic=402