On how many services are you benchmarking? Usually we suggest a new XI server at 20k checks. Are these all passive?
I would definitely, 100%, not recommend an offloaded db on a system this size, but again, I'm not going to argue with your benchmarking if you are benchmarking with that many hosts and services. I've heard from other techs that they suggest not offloading the db at as low as 10k checks (there are a lot of variables, so definitely there is some fluctuation).
As far as doing a remote, if you go to
https://support.nagios.com/tickets/ , sign in, and create a ticket (referencing this thread), I can do a remote. However, with that many checks, I can't guarantee we can make it functional.