Why not try
Mediatemple - their grid servers are promising and if interested let me know I can provide a 15% discount coupon.
Mu company has a server (Extreme DV hosting) there which hosts more than 158 sites (demo sites, company website, email, multimedia content, license handling, cart and more than 90% are pligg sites) atp and all work fine with a daily combined unique visitors being 80,000 (average) - but if you consider the page views - it is almost 3 times at 250,000 (14 engineers of our company, clients testing their sites and users accessing sites and content frequently).
We have successfully recommended more than 18 pligg clients to use
MediaTemple and it works pro :) as a developer we get no complaints, more business and better customer satisfaction.
MediaTemple do have a money back guarantee - I am sure you can give it a try, btw: they have 24 hour phone support, their support ticket Account center is very sexy and easy to use, they also have local support phone numbers for almost 11 countries (not sure if it is 11 or 15 countries). Also their servers are scalable - today you can start with a lower end machine - tomorrow if you decide to move to a larger one - just pay the upgrade fee - they will smoothly migrate it - with all your system intact - no reinstallation or reconfiguration absolutely needed (for 4 of our clients they started with DV Basic, then migrated to Rage and now in Extreme with almost no developer intervention at all)
Use the link:
http://www.mediatemple.net/go/order/...eatinnovus.com
for discount coupon - while in the last page of purchase where you select the hire period for the server, on the right you should see referral domain enter "greatinnovus.com" and in special promotion code enter "kirupa07" without quotes to get the discount processed.