Re: 1st stage....
1. congrats on the new venture.
2. are you planning to retain those cabin doors+windows? if yes, then i would never recommend sanding. alternatively its better to strip off everything using the nail paint remover ONLY and prime+paint it white.
3. lastly from the looks of it, I think the donor is an AF B773ER. if so, then please paint the rear hor. stabs grey as they are white on the donor but, L. Grey on the PAL.
* - guess a more apt donor would have been the EVA Air B773ER by Hogan, and to top it all it would have costed pretty much the same as AF, although it invloved more stripping work than on the AF, but that shouldnt have been a problem since you would paint it white. just my 2 cents worth...