brand new but experienced at building bikes

I have been doing research for about a month. I am going to build a board track style bike for my son. I like the manic mechanic motor mounts and the drive sprocket adapter for starters. If I use this type of drive sprocket adapter can I get away with a 14g spoke rim? Or I also like the disc brake drive sprocket made by Top Hat it looks like it works. Please give me some feed back these to me seem to be the most important starters.