Server to buy from a decent provider ...

[Gerbert]

ASVhost.com and black.host servers are attractive for me and I have to select the best one, so what should I do?

[President]

I would highly recommend GTHost.com instant dedicated hosting (https://gthost.com/instant-servers/) to any people not happy with their current host.
I am able to focus on my business instead of worrying about my site's uptime, since all that is taken care of very well. Low-cost trial starting at $5/day.

[№Lucky]

I have been with zakservers.com offshore dedicated servers (https://www.zakservers.com/offshore-dedicated-servers.php) for just 8 months, and (so far) I have been positively surprised.
They were extremely patient as I cluelessly asked for various ports to be opened to allow extra functionality on one of my sites.