R640 10 bay add NVME option , what parts

Am considering purchasing an R640 with 10 bays.  I would like to have some of the bays support NVME.

Is my understanding correct that as long as I purchase an R640 with 10 bays I only need to purchase a few cables to add the NVME option to 4 or 8 of the bays. ( I will not need 10 NVME bays )

Either one of these cable assy will add 4 ports of NVME to a 10 bay R640

Dell Assembly Cable NVME 6-9 for R640 10-Port Chassis 6PPNG

https://www.ebay.com/itm/175631276721

Dell PowerEdge Server R640 10 Bay NVME 2-5 Cable Assembly F2V74

https://www.ebay.com/itm/363518084013

So here is a 10 bay R640 without NVME

https://www.theserverstore.com/Dell-EMC-PowerEdge-R640-10-Bay-Server_p_910.html

and they want $500 more for one that supports NVME

https://www.theserverstore.com/dell-emc-poweredge-r640-10-bay-nvme-server

Could I just buy the cheaper, Non NVME, 10 bay server and add one or 2 of the listed cables and then have NVME capablilites on 4 or 8 bays ?

thanks in advance