Seems reasonable to me ...You might think about a slightly more powerfull motor than suggested.. (don't know how it flies with suggested one) Also check out this one http://www.horizonhobby.com/Products...?ProdID=MAOUSD
looks like less work.. But remember adding the vvp and the extra servo will effect the cog and sometimes the moving the battery in its suggested area will not compensate for it, so I tape everything in place and move it around until its right...
Good Luck!!