a lot of things are theoretically possible. Triathletes put such great demands on their bodies to begin with. You will likely wind up choosing one or the orther. I would suggfest you buy a few pounds of gluten in bulk (about a $10 cost). You will also need to get handy at using it. Seitan is the same thing. Great stuff for upping protein quality. You don't need much at a time. I get my protein powder here... http://www.proteinfactory.com/
Best thing about these guys is the price. Having played with most of these things, I would get 5 or 10 pounds of milk protein. It's works, mixes well, and it's cheap. Egg protein is also ok. Avoid the fancier stuff like whey. Since you will be consuming large amounts of bean protein, avoid soy powder. Wish I knew of a multivitamin to advise you to take. There are a lot of good ones, but they all have too much of cheap vitamins and too litle of the expensive stuff. I take one called Alive, it's ok.