The ID should be the iMacPro1,1 because you have no provision for integrated GPU. All the X299 builds I know of are custom Vanilla builds created with Clover Configurator and KEXTs. I've never heard of anyone getting Multibeast to work with an X299 yet. What other Mac/Hack are you using...
Yes. In a X299 with i9-7980xe, 128GB of RAM, and Vega64 GPU. The HP EX950 replaced a Samsung 960 Pro ($275 vs $1250). The HP drive is slightly faster. So, yes. I used it in a very custom, difficult Hackintosh build.
If those SSDs are what you own, fine. There used to be a problem with the 970 EVO+, don't know if there still is. I own 2 - 2TB SSDs a 960 PRO and an HP EX950. The HP drive is faster for almost all scenarios and it is less expensive.
Spend the extra coin for a ASRock Z390M Pro4.
Get Fenvi FV-T919 AC1750 Dual Band PCIE Desktop Wireless Adapter
Most of the SSDs out there work well.
Get HP EX950 SSD. It is faster. I have the 2TB version. Works great.
I have a couple of older boards I support for cousins, son. I had to go to UEFI to get everything working even through they were beta UEFI BIOS. If you can get UEFI BIOS, try to work through it for your board. If not, Get try to get a used Z68 Gigabyte motherboard. Their Beta UEFI...