Yes and no. RAM needs depend significantly on the performance you need and how you use the server. Use it for CIFS shares only and you can probably get by with less RAM. Try to run dozens of VMs with ESXi + NFS and you can expect to need much much more. The best advice I can give is to read up on what others do and try to match their systems(assuming they aren't complaining about it being slow).
If you aren't in IT and/or willing to spend a few weeks getting familiar with the software and what you can and can't do and such, then you should see about hiring someone to build it for you.
Now for an unrelated comment. BackBlaze storage pods are super cool. The allow for extremely dense configurations. But only 2 people have used them here that I know of and both had significant problems with the hardware. Port Multipliers are the "poor man's SAS expander". As such, you get what you pay for. They are not particularly reliable and can cause significant grief. If you aren't in IT and in a position to take the server offline and troubleshoot port multiplier issues(which may not give you a warning like "port multiplier error on port 2") then you should seriously consider using a different setup. For both of them they setup the server and it worked great.... for a while. Then things got mad ugly and they ended up tearing the thing apart to find the cause. One person could only narrow it down to "hardware isn't really compatible with FreeBSD". Later he posted something like "second backblaze server running Windows went down for a reason that can't be identified... backblazes just don't seem particularly reliable".
So please do your homework before you jump into this. If you think you are in over your head consider paying someone to build one for you. They should be able to help you rightsize your server without hardware reliability problems and without buying too much extra hardware. LOL. The first mistake noobies make is buying too much or too little hardware. ;)