Firstly, congrats on getting to the sales stage!I am listing the S700 for sale now. You can purchase yours here.
Please ask me questions before purchasing if you are aren't 100% positive of compatibility.
Second, Questions:
1. Will the Gigabyte Aorus Xtreme (XL-EATX) fit?
2. You say at least 12" custom PSU cables, but do you have approximate measurements for standard 12V EPS and ATX plug locations?
3. On 280mm Radiator support, what are the exact dimensional limitations and/or known incompatibilities?
4. On the 500mm riser for the rear: Do you have any pictures of this option, namely if one wanted to try and source a Gen4 riser in the future, should be be looking at straight on, or 90 degree terminations?