I have three websites hosted at Cloudarion.com web host. Their VPS hosting in Switzerland is reliable.
The combination of quality and cheapness makes them attractive for the greater part of the web masters.
QHoster.com and hostsailor.com are worth trying because of their top-notch services.
Their servers come with one of the industry's most complete set of standard features and services at no additional cost.
I know affordable vps hosting accounts in Ukraine offered by 3v-host.com professionals.
I believe this web host is flexible and stable enough to satisfy all your specific requirements and keep your web sites always online.