Ideal version/server platform for a Clean slate?

[Shinkaze]

Presently we have vB 5.1.1 installed on a shared hosting environment.

The software is proving to be highly buggy and not only have I been receiving php errors we have received a number of known 5.1.1 errors associated with phpv5.4

Luckily our community has not been migrated in, so I can set this thing up right the first time and I would like to achieve that.

1. Hosting platform. Shared -> Amazon AWS
   In researching the AWS marketplace, there does not appear to be a "default server instance" designed for running vBulletin. It's easy enough to find pre made Wordpress and other CMS server builds, but I do not see one for vB, much less vB 5.1.1
   Need to know: What is the most stable server config (OS flavor, php flavor, db flavor)
   
2. vBulletin Version
   Management has declined to use version 4 due to UI/UX. We need to build off v5. v5 appears to have a number of known and unresolved errors and functionality misses. For example there is no external.php, nor do I see how to pull RSS information from v5. The bugs we are seeing in v5.1 are solved by moving to 5.1.2alpha, but that opens up new bugs int he alpha version.
   Need to knowWhat does thevBulletin.org community believe to be the most stable v5 version upon which to begin building community?
   
3. Management and monitoring
   I have some familiarity with vb3, it appears that vb5 is similarly structured. This leads me to believe I should install a server monitoring solution as well as look for some sort of managed bulletin service.
   Need to know: what does the community believe to be the best monitoring and managing service?

Thank you in advance for any advice given as to an ideal reference build.
This is an opportunity to build out a community from the get-go and we hope the vb.org community can offer up some learning on the most stable foundation upon which to launch.

My Best,
Adam