Hi deltaforce, welcome to NeuroTalk.

I'd first think of the textures or/and tastes that your son will eat and then I'd work at incorporating a supplement into that. I totally understand your difficulty trying to get your son to eat different foods and to take added supplements. It's not easy!

As mrsD said there are many products available these days, esp. in the US if that is where you are, that have added omega3 etc..

I looked up the Brainwise and I take it that was a "smoothie" type product. I'm sure there must be something else similar in texture if your son took that easily.

Coromega have a range of products but one of them is called a "squeeze". It is fruit flavoured and if your son will drink a smoothie, you could put it in there. I think there is a custard too, but I couldn't find that info.. I just remember it from an autism group I was with years and years ago. Just check the ingredients on whatever you decide to try in case your son is intolerant to certain things, like eggs etc..

So ... I'd start with what he will tolerate and go from there.
Let us know how you get on.