Desktop or laptop? Will you be working wirelessly or sitting at a desk next to it for major data transfers?
You're going to want something that does caching, and ideally 10gbps. I'm pissed off at Synology right now - even as I propose their solutions in most cases - due to the lack of 10gbps support in the mid-line NAS models, thus requiring a caching card OR 10gb card debate.
I'm going to flip things a bit and make the recommendation backwards - based on disks and performance. You've got 8tb of data now, so I'm thinking that 16-20tb is the range to be in - plenty of space, since NASes don't like to be full. I'm going off of NewEgg.CA for pricing - damn, this hurts. The Seagate IronWolf's are $310 for 8tb, and the 10tb's are $410. The SkyHawks are a few bucks cheaper each, but I'm not sure the tradeoff is worth it. So to do a RAID5/SHR1 of 3 disks gets you 14-18.x tb of usable space (and you purchase 4 disks so there's a cold spare in the event of a disk issue). So you are quickly $1,300 into spinning rust (hard drives).
If performance is big, I highly recommend the ability to leverage SSD's for speed. QNAP does Q-Tier, while Synology does caching. Both improve things when doing lots of disk I/O - if nothing else allowing writes to the SSDs while doing a whole lot of reading from the hard drives, eventually writing the data to hard drives as performance allows. Figure you'll add 2 250/256gb SSD or NVMe drives to work in tandem with the hard drives above. Add $150 to $200 to the cost for the NVMe/M.2 SATA/2.5" SATA drives (depending on what model).
Next is the network speed - I really like 10gbps ports on NASes since it prevents you from having to purchase a switch that can do link aggression to 10gbps for your computer. I've got a Netgear GS110EMX for the DS1817+ and DS716+ units to do link aggregation, and 10gbps from a TB3 adapter (Sonnet) or PCIe cards (Asus). Only issue is I have a second switch stacked with it that does PoE for my wifi and other gear, so it's a trade off between options. Some units only have SFP+ for the builtin 10gb adapters - there are a few options like a 10gbps switch QNAP qsw-804-4c or Netgear XS708Ev2. I'm more a fan of a direct connect with a $30 eBay Mellanox MNPA19-XTR cards with cable - yes, $30 with cable for 10gbps networking. QNAP has a new TB3 adapter that's either SFP+ or RJ45, so it's another option for direct connections
https://www.qnap.com/en/product/qna-tb-10gbeWith that said here are some models to consider:
QNAP
TS-332X -
https://www.qnap.com/en-us/product/ts-332x/specs/hardware (It's on my to play with list)
This unit is a fill it & done recommendation - there isn't much expansion with only holding 3 disks, but it has 3x M.2 slots for caching, and 10gbps via SFP+
TS-673
6 bays, 2 M.2 slots and 2 PCIe slots for either more M.2 drives or 10gb cards. More expansion & growth options.
Synology
DS1817 - 8 bays, use 2 for SSDs and put in that 4th drive and run SHR2. Gives you 14-18tb of space, with double disk redundancy, 2 SSD drives for read & write caching, plus 2 drives for expansion. Builtin 10gbps RJ45 so plug and done.
DS918+ - 4 bays with 2 NVMe slots on the bottom. No 10gb option, but with a switch you can aggregate and get a bit faster.
DS1817+/DS1819+ - 8 bays and a 10gb/SSD debate. Can aggregate 4x 1gb ethernet jacks, but for the same price just do the 10gb card and use 2 of the drive slots for SSD's. More powerful than the DS1817, but not sure it's worth the $
-Joe