We do not recommend any particular dedicated servers, as there are too many providers and what server works for you will greatly depend on your traffic locations and what you want to do -- better to have a systems admin on payroll who helps you make this decision and manage your server.
If you do need some recommendation, try LiquidWeb, OVH or LeaseWeb.
If you want to source a cheap dedicated server, try ServerBidding by Hetzner.
Most of our users use Vultr. These servers are excellent -- the only issue is that they don’t give any support for the installation. You need to do everything yourself (except the OS that you install in just one click).
However we provide a deployment manager that makes it easy to roll out a new installation on Vultr. See here for more details.
Contact us at the support desk if you need further assistance.