A few comments on what I see there.
1. This is just personal preference perhaps, but if I were you I'd have a sink with a sideboard on it. That way you can lay down a kettle on its side to clean, or a keg, or anything for that matter. Plus, you can use it as, well, a drain board. No bending over to use it is a plus for me.
My setup uses an old metal sink but you can see how easy it is to both keep stuff by the sink during and after cleaning, and also to spray things out. I have a sink sprayer which I consider to be superior to the one you have listed where it comes down from above. Maybe the best solution is have both, i don't know.
Here's what I mean: the sink drain board extends to the left of the sink, and I pulled out the drawer and made a little plywood extension; both are covered with a rubber mat. You can see the sink spray hose to the right of the faucet.
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Here's a wide-angle of my brewspace; the entire back wall, from back of sink to left of the green ferm chamber refrigerator: 13 feet.
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Those sinks like you listed can be had with sideboards. I personally wouldn't consider a sink without one.
2. You listed $500 for a nice mash tun. Don't know if you're estimating high or what, but unless the capacity is huge, you can do it much less. Here's mine; it's a basic kettle, holes drilled for ports and valves and thermometer and such. I have some reflectix around it to hold in heat, and with the RIMS works great. It's 10-gallons, so for this I'd expect a price closer to $250, maybe $300.
3. Since you can only do this once, do what you want. Skimping now will cause heartache later as you wish you had something you didn't do. I'm not saying to waste money, but rather to be generous in your planning for electricity plus some flexibility.
I note in the mockup that you have a stainless table next to the sink. Maybe that could serve as a drainboard (sort of--no draining), or perhaps turn the sink 90 degrees to the right and have one with a drain board.
That's the sort of thing I suspect that, later, you'll wish you had.
Further, expansion capability and flexibility are key here. I've revamped my brewspace serveral times to accommodate new equipment or setup. So the idea that you know, with certainty, how you're going to want it arranged....well, i'd bet you do some tweaking. Allow for that.
All of this is my 2 cents. Great fun to plan something from scratch like this. Wish I had a space like that.
