OK, I'll bite!

(((keep in mind I have no pool, and when I get one it will be AG. But here are my thoughts anyhow.)))

If I had to pick and choose from your list, and could not get everything, I would do the following:

-Plaster (diamondbrite is gorgeous, but I'd rather put that money elsewhere; maybe a tinted plaster)
-salt system (high priority)
-spillover spa (best of both the spa and waterfall - 2nd priority)
-deep end, but skip the diving rock (most rock work is $$$)
-tanning/kid area
-Polaris if I had a lot of trees/dirt nearby, otherwise wait on that.
-have extra lines plumbed/electrical done now for potential future improvements

Hope this gives you some insight.