I need a high traffic vbulletin host

you can try vps or dedicated server
try to use ovh.co.uk
liquidweb
hetzner
leaseweb

i think this may help

 

you can find high traffic in ejtema.net

 

i preferred u rackhost.biz they r to much good and have cheap plans

 

Is your problem mostly security issue or server load issue?
If it is mostly security issue, you need to find a host who is most familiar with vBulletin forum software.
If it is just a server load issue, you can get a dedicated server. Many of them are under $100 a month.
In some cases, beside upgrading hardware, you may need to fine tune your database for high traffic serving.