Hi Alain,
surely by now You have to admit that it is very delightful to string once You get Your knots equally small and fine.... it became quite an obsession with me, even though I very seldom undo my designs since I simply make the classical type of pearl necklaces. Still check out Firmemountain.com for twisted needles (fine, medium and heavy), get silk in size E or Power Pro. With this kind of material Your knots are even smaller when using relatively large pearls. Bullion thread and a nice clasp will make your work look very professional indeed!
The only danger is that You become such an addict as I am so You have to buy pearls all the time to be able to string......
Otherwise practicing will make You a great stringer.......
Give us pictures from future projects and let us know what Your wife thinks....