Why not found a start-up company and hire 2 - 4 full time developers and 1 project manager? Moreover, I believe MSC could attract many capitals too.
I think the right choice is the one that makes JR to commit 100% of his time to the project. You can bet that competition will commit full resources of their founders to their project.
Half-measures are not good for such a project. If the "buy back" is needed for JR to go "all-in" in MSC, then I strongly vote for the buy back.
Many people have said that they think it is imperative for JR to be on the project full-time, yet I have not seen anyone provide a reason as to why his full-time commitment to Mastercoin is necessary. Presumably the community feels that since JR conceived Mastercoin it follows that its development is dependent on him. But it's one thing to conceive an idea and it's another thing to develop it. Does anyone have reason to believe the JR would be such an exceptionally good developer? Are we really so sure it would be impossible to find a developer of comparable skill?
I find the community's attitude towards JR untenable, and I partially blame JR for not being more direct with the community: either he believes his full-time help is necessary for the development of Mastercoin, in which case, if the community and the board agree, we should do what we can to get him on board full-time. If on the other hand JR doesn't think his full-time commitment to Mastercoin is necessary for development, he ought to say so explicitly, that way we can stop focusing on how to get him to commit to the project, and start focusing on the project itself!
In my opinion, JR obviously doesn't think his full-time commitment to the project is necessary for its success, otherwise, he wouldn't have published his white paper without any code, and wouldn't have explicitly said that for two years he tried to convince someone else to undertake this project.