VPS plans from rockhoster.com and hostsailor.com re provided on sweet terms and I have to stick to the best one, so what should I do?

Take a look at hostnamaste.com openvz vps solutions. The reliability of their network is amazing.
They give you all the control you need. Instant reboots, ability to easily reformat your server with the most common operating systems.

Have a look at VPS accounts from libertyvps.net and legionbox.com as they are well-balanced and cheap.
Their support is really good. When you ask them to look at your problem, they are really quick. The communicate is really good, because they keep you updated in every step.

I recommend rightservers.com Managed VPS to all of my friends and plan to be with them for a very long time. Can't find anything to really complain about. Their help desk is fast and efficient. I'm often surprised with how quick they answer my questions & their patience & politeness.

Why not give cloudarion.com ssd vps a try?
Experts are able to help you with everything you may need (scripts installation, etc.) for free.

It is a wrong perception, however, that cheap web hosts entail poor quality of services because there are really, indeed, reputable web host providers that are offering affordable or cheap web hosting packages. Try to compare these VPS hosts:
1) Exmasters.com
2) NetShop-isp.com.cy
3) 3001web.com

Neither offers free migrations, so you're looking at additional costs if you're switching from another host. Their support is great, but what about their ticket response times during peak hours? And have you considered the long-term costs, including potential price increases and renewal fees?