Looking for a new (Synology) NAS?

Hi - I need a bit of advice...

I have a Synology DS916+ running DSM7
8Gig Ram, 4 x 6Tb disks currently 5o% full

I'm looking for a new (chassis-only) Synology to replace the DS916+

Would like to be able to upgrade Ram
4 or 5 Bay
2+ Gig Lan Ports
NVMe

What do you recommend ?

-Tom

It would make sense to upgrade with DS920+ or DS1520+. This is a replacement model for DS16+ series. You will get much better performance, newer graphics, NVMe cache and option to upgrade DDR4 RAM.I hope this helps.