Managed host with webforum experience

[wxdqz]

Preface: I have a mid-size forum running VBulletin (.5million posts, 500-1000 users at peak times, growing quickly) that is becoming a real pain to handle. I'm currently on unmanaged hosting which was financially necessary when it was first setup.I don't have the time to manage the server anymore, and I would like to move to a company that is able to both manage the server entirely, and also assisst intelligently with the scripts (vbulletin in particular) - someone that can manage the server with an eye to what is required to keep a fast-growing php/sql site operating well, as well as diagnose and correct issues when they arise - and if it means going into a script now and then or advising on precise corrections, that would be a plus.Location is north america, my budget is flexible (400/mth is an upper limit, but not hard), my coding knowledge is moderate: I know what needs doing, but I don't have the knowledge or the time to invest in getting the knowledge to do it myself.I hope that's not too vague. I see a few others in this forum with a similar problem, but the 2 threads with the best advice had very specific problems that don't apply to me.Suggestions? Thanks in advance.Or, is the better bet to stick with unmanaged hosting (I'm with the Planet right now and they provide fantastic UM services) and go with a sysadmin company?I would probably go for the sysadmin company as if you pick up a good one, (do some searches but PSM comes out quite well) it means they will become familiar with your site and should you ever need to move to a bigger server they can help migrate. Also it means that if you don't like the management you can swap without having to change datacenter