Dell offers a custom ISO
You have requestet 6.5
You have to download the ISO when you like to install it via virtual CDROM(iDRAC). This iso is the same for all other dell servers as well (R730,R740xd,R5x0) and it doesnt matter if you have dual SD card, BOSS or raid1 HDDs.
Next time please visit dell.com/support and enter your service tag or select "choose different modell". You will find the ISO in der Driver Download section after selection "ESX xx" in the OS dropdown.