T5810 support of dual gpu, SSD, NVME, TB3 for hackintosh/Proxmox

Hi. :)

I currently have two Dell T5810 that I got a few months back for a low cost homelab for college/learning and experimenting with.

I need to set up multiple operating systems and was seeking some hardware suggestions from people with more experience.

I have to run windows, macintosh, and linux for school.  Specifically i'm running video editing on different operating systems (final cut X only runs on mac for instance, davinci resolve has a linux version) and I also wanted to learn Proxmox in case for some lighter programming and AI experimentation that in any way affects things.

My first question is to clarify the support of each motherboard slot.  My understanding is that PCI bifurcation is supported in at least slots 2 and 4, someone suggested also slot 1 but I wasn't sure on that. (was also suggested slot 1 is only x8 electrical)  I was undecided whether to run 2 or 3 NVME drives but it seems like me 2 drives could bifurcate in slot 1, using an add in PCIe card so that I don't lose a second GPU slot.

I know slot 2 would cover slot 3 if there is a doublewide GPU in there, but does it actually disable the slot?  If I were using only a singlewide gpu or tried to use one of those bitcoin riser cables I wondered if there's any way to run any useful cards in slot 3.

I'm told slot 5 is suggested to use with the Thunderbolt 3 card if used - i'm not even sure if I can find one (searching ebay turns up nothing) or how much they cost/if too much I wont be able to use this anytime soon, it's more of a nice to have.  If I dont use it for TB3 I was wondering if this is a full speed x16 slot or if it had bifurcation/what else the slot could be used for...  (could I also run a gpu there if it fits or is it limited to like SAS/RAID cards and such)

I'll explain more after I figure out what I can do with the slots in the first place.  Thanks for any suggestions in advance...  :)