hi Richie, I know the kit of the ALR intimately as well as the plans and the instructions.
My best advice to you is to follow those instructions word for word and step by step and you shouldn’t have any difficulties.
They were written by a modeller for modellers who was fed up with building kits with great wodges of areas missing that needed explaining, and as such wrote the instructions as he designed and built the prototype.
They might be a little long winded at times but they try to explain any of the pit falls for a novice builder, at every stage.
As for motors you will not go far wrong with something similar to 555’s operating on twin speed controllers as she has a great manouverability with individual controls and that size motor will give a good scale speed….remember the real boats would only do 7 – 9 knotts with a wind behind them!
Give it a go and try it.
.