NVME for the boot drive, no less than 256GB. SSDs are nice and all, but they're quickly becoming yesterday's tech. Since you're into gaming/streaming you'll probably want it larger, for a better size temp folder (
512GB+ would be more suited).
32GB of RAM is fine, but 64GB is better. It depends on whether you want raw speed for gaming performance (expensive low-latency RAM) or slower RAM but twice the amount (64GB of RAM to give to Primocache, Primo Ramdisk, etc). Less/faster RAM will speed up games, but the system will have less versatility. More/slower RAM will lose you a few FPS, but overall the system will be more versatile, have a larger L1 cache for Primocache, enable you to make a RAM drive to install games directly to so they load faster (even faster than a NVME would). I went with the more/slower option, and am thankful I did. 64GB of RAM in a machine really makes everything fly, and gives you tons of headroom.
As for storage I'd recommend multiple 4TB or 8TB HDD drives, coupled with
Stablebit Drivepool so you can have redundancy (pool/folder/file mirroring) on either all of it, or on just the folders you specify. It makes many disks look like one large disk, and has a ton of features. I'd also recommend Stablebit Scanner, to keep an eye on your drives (monitors SMART data, temps, scans surface and file systems regularly). It also tells Drivepool when a drive is expected to fail, so that Drivepool can evacuate contents of that drive to another in the pool.
For backup/mirroring, Stablebit also has
Clouddrive, which interfaces with a bunch of different cloud providers and can give you further options for your data (and a pool if you use Drivepool). i.e. if you had 2 8TB data drives in your pool, you could add 16TB of cloud storage in a Clouddrive volume, and mirror all of your local storage to it with zero effort.
If you don't have enough cloud space for backups/mirroring, you can look into adding another HDD and using
SnapRAID to do parity snapshots on your main data drives. It's free, and fairly easy to use. Personally I use both SnapRAID and Clouddrive in combination with Drivepool, Primocache and Primo RAMdisk.