^ Are there any sanctuaries that would be willing to let you start volunteering and work with animals more once you proved you were truly serious? You'd need experience and some training anyways. That could take years, by then you may be able to afford the land you'd need.
I'm sure you know who to PM and discuss that with, if you haven't already.
Anything in the world...that's a tough call, money could really help get some things....but not what I would want the most.
Health, it would be nice to not have to deal with pain - bad genetics on my part leaves treating/dealing with it as the only option.
Or maybe the mental ability to actually be really really good in math. There were always things I wanted to do but I just don't have the ability that would enable me to get the strong math foundation I would need.... and I hate failing so that's always bothered me so much. Similar to that would be to know multiple languages (fluently), same parts of the brain are used for this and math.
Edit.... Reweighing wants/needs... Yep, math ability. I'm the odd one wishing to be smarter.