Hi in my experience I find it easier to firstly work out how much space you have available as every ones turbo systems cooling systems ect ect can be different in there lay out once you know how much free area you have you can purchase one as close to your measurements as possible or the best is have one custom made to your specifications hope this helps.
Your right. All I came across was two second hand coolers both from busa. Not even a close fit. Now I'm thinking doing a water methanol magic. Aem looks ok, tank is an issue yet. Prize is half the mcxress cooler.
Removing oil cooler would make more space but it's not plugandplay option either.