While twin props are generally best with counter rotation, it usually means on a single hull, preventing torque roll and enhancing the effect of the rudder. In an application like this, wide and no rudder, it should make no difference at all.
While the ESCs should be OK, it is as well to remember that Hong Kong amps are much, much, smaller than other peoples. The accuracy of the placement of the decimal point seems a bit casual at times, as well. For about £5 each more, you could go Mtronics with full size English Amps and an enforceable warranty - your dealing would be within the UK and protected by UK consumer legislation.
It might be worth a visit to the Temple Park Centre on John Reid Rd in South Shields 24th or 25th March. Hopefully a good selection of traders to talk to at the North East Model Boat Show.