I believe that raw wheat is used in traditional Lambic making. Part of the reason for the long and convoluted turbid mash schedule is to leave some of the wheat starches unconverted so that they provide food for the microorganisms at different stages of fermentation. It seems like you are plannning to provide these starches with maltodextrine. Hitstorically, before the science of Lambic making was fully understood, wheat was added to Lambic to get around malt taxes.
Torrified wheat and flaked wheat are pre-gelatinized, obviating the need for a gelatination step in the mash. Both are pretty readily converted into fermentable sugars when mashed with a high diastatic base malt. The torrified wheat is "puffed" after gelatination and should be milled, whereas the flaked wheat can be mashed as is.
You can really use either. Wheat typically makes up 30-40% of the grist for Lambic. Use what is easiest for you and your process. As Yoda above states, time and patience and the action of the various microorganisms that produce the flavor profile of a Lambic will likely have a greater influence on the outcome of your Lambic.
Since you will have a lot of time on your hands while you're waiting, there's a decent article here about Lambic Making:
http://brewery.org/brewery/library/LmbicJL0696.html
Good luck to you, and let us know how things are progressing. Apart from the time involved, this is an exciting venture!