The list of recommended NAS’es is here:

https://www.amazon.com/s?k=nas+2+bay&linkCode=ll2&tag=mimograph0d-20&linkId=0c7338943e2306d6823af1215a569470&language=en_US&ref_=as_li_ss_tl

TerraMaster F2-210 2-Bay NAS Quad Core Network Attached Storage Media Server Personal Private Cloud (Diskless)

it has 2 bays, pretty affordable and has enough capacity for your purpose

Asustor AS1002T v2, Marvell Armada 1.6GHz Dual-Core, Personal Cloud (2 Bay Diskless NAS)

this one can accommodate up to 24 TB which is way more data than you even have now

There is a better and bigger version for sale now for just $200:

TerraMaster F4-210 4-Bay NAS 1GB RAM Quad Core Network Attached Storage Media Server Personal Private Cloud (Diskless)