Much appreciated m8. I ordered these.it is the same thickness as the stock card, just the 2 40mm fans are slightly tilted so they extend the thickness by like 3mm which is still fine for the sentry case afaik.
these are the adapters I used, I will probably solder the gpu fan connector to the 4 way splitter directly to slightly reduce cable clutter around the card.
And my Challenger arrived yesterday! I'm ready for this case to arrive now.