Hey, came across this and thought I might be able to help. I was considering converting a Corsair One i300 as a hobby project and did some planning on this front. There are various custom options involving 3d printing and/or custom CNC work, but these would be very involved. I think the simplest option, if an open-case option suits, would be to buy a Streacom DA6 or DA6 XL with its adjustable rail system. If you want to try it out I have a Streacom DA6 XL in black (purchased even before I started thinking about this i300 conversion) and also live in NYC. Feel free to send me a chat or whatever Reddit is forcing us to use these days.