Low cost VPS in NL
 

I know hostsailor.com and libertyvps.net provide nice VPS deals in NL and I'd like to know which one is better to stick to host a heavy web site with?

I recommend you to look through Rockhoster.com Netherlands VPS deals. My website response times have never been faster and support level is above and beyond. If you are thinking about switching, this is the host to go with.
Good range of price plans and options for the novice to the expert.

Well, Libertyvps.net is the host you can rely on!
I moved my personal site to them and was so impressed with their service I ended up moving all my sites with the exception of one (it will be moved next week) to them.
Reliable uptime, and decent customer support!

Both mentioned companies - hostsailor.com and libertyvps.net - are worth trying.
You know, with their VPS accounts you will be able to have faster speed connection and more useful features included into it.