Lookin' awesome so far
I gather you mean me when you talk about Greg and the heaters and sock overflow ...
I drilled my sump for a return pump and an accessory pump
The first time I hooked them up I had a small disaster
Long story short, I siliconed the holes shut and now run my return and acces pumps internal
Nothing like having flexibility when the tank is not drilled

Plus, the less holes in the glass the better
I like where you are putting your heaters as they will not be bypassed like mine can - potentially
Are those sock holes 7" ?
Keep the pics coming