It appears that the head is still very new, enough so that the possible spring choices is limited more than it may be six months from now.
I can tell that the members in that thread do not know how to maximize the camshaft and springs etc. The wrong way to set up any cam or springs etc, is to advance or retard the cam to clear the pistons. Any cam is supposed to be designed extremely specifically to provide specific opening and closing events. It's far more complicated than almost anyone ever discovers, unless you get to read a lot of the comments of a real cam designer.
I cannot say if Jay can make cams for those, he has often mentioned working with new heads of another kind to learn about what the head likes.
You have read enough to have heard of an AFR head, a TFS high port head? Those are radically different heads, they look similar, but the cam makes tons of difference in how they make power. A custom cam for an AFR will make more power with it than if it's used with the Canfield/TFS heads. A custom cam made for a Canfield/TFS will make more power with it than if it's used with the AFR heads. The cam designer actually gets tons of extra power by taking advantage of the head design, without compromising other things.
I don't know how else to say it, I'm not a designer, just a person who has read of amazing things from not so special parts. The combination is magic, so try really hard to get a best match between the heads, cams, and intake. Half of the budget "might should" go there. Mine did, I have an equal amount in my shortblock as I do the heads, cam and valvetrain.
The block is another subject, you have a modular and those are inherently expensive. I have to jump up to a $2000+ block to safely reach 500hp. Hopefully Jay can do those new TFS heads(cams).