Need Advice on Server Specs for XenForo

[twenz]

I'm looking to convert a site I manage over to XenForo from a forum platform that is completely managed by the forum provider (they provide the software and do all the hosting, tech support, etc.). Given the situation I don't have any idea of what server specs would be needed to run XenForo optimally. The site sees about 500 posts a day during the peak season and about 100 a day during the low season (seasonal interest). Any ideas for what type of server setup would be needed with something like AWS?