So we forked from SMF 2.1 beta 3 - I couldn't recommend working off that unless you're already super familiar with it as a thing, simply because it's still lurching towards an RC and has been in beta for 6 years.
2.0.15 is out and is stable and is a viable base for general foruming. But then again so is phpBB, etc.
In terms of mods available for SMF specifically, there haven't been any points/currency mods that I've seen lately that are still in some semblance of being kept up to date meaning you'd need to roll that yourself. Potentially the same for any other forum software, though I know that XenForo has at least one points addon that could conceivably be repurposed.
In terms of the other stuff you're talking about, I think you'd need to look at implementing these yourself, not sure how complex or fancy you're looking to get though.