Yeah, thousands of users is much more than the optimistic version 😀 I’m sure I don’t threaten. 1024/2048 (burstable) VPS should work fine. Thank you very much!
WP+BP might be your option if you can afford a good hosting.
You mean that this “compilation” may be a tough row to hoe for a typical VPS (comparing to i.e. Drupal)? Sorry for stupid question, it’s my first contact.