When it comes to the selection of radio equipment everyone has his own idea of what is the best, relative to price. Obviously, if you are prepared to pay in excess of $1000 you will get an all singing, all dancing unit, most of the functions of which you will never use on a model boat, but it's not necessary to pay anything like that much for a very capable outfit.
I came to model boating about 14 years ago from RC flying, and some of my radios were state of the art (at the time) and far more capable than I needed for boating. A few years ago I was introduced to the world of 2.4 Ghz and bought a couple of sets from Hobby King. One is the HK branded unit, a good performer, but it has the drawback of needing to be connected to a computer to change the settings , not a big job, but inconvenient. Another I have is also from Hobby King branded Turnigy, which cost me the grand total of $50 Australian, delivered to my door. This is a 6 channel set with servo reversing switches on the front of the case, is easy to use and has all the range I need for boats, plus connection to a PC is not required. I've never had a moment's trouble with it.
Then we come to Electronic Speed Controls (ESCs). Again, everyone has his favourite, but I use Mtroniks almost exclusively, and again, have never experienced a single problem with any of them. The ACTion brand are excellent units, beautifully made, but are considerably dearer, at least, they are here in Australia. I do have one which is a combination twin ESC and mixer, and it is a fabulous unit. I'm sure other members will have different suggestions for you, so in the end it will be up to you to decide.
You are probably already aware of this, but be sure to provide access to all the electrical and mechanical components so you can easily get at them if necessary. You will also need access to the rudder linkage so adjustments can be made if needed. Our club sails in salt water which can even cause brass to corrode, so I remove my rudder posts from their tubes periodically to lightly coat them with grease. All my boats have hatches installed over the rudder assemblies for this purpose.
I look forward to seeing further progress on your model.