I have done BFL and BFL for Women several times although I really never could stick it for the full 12 weeks on either program, especially BFL, which simply was too limited in allowable foods for me.
That said, both are great plans. I was entered in the official BFL contest the first time around (but only made it through 10 weeks) and I bought supplements then because it was my intention to turn in the documentation as required by the contest. I also got "deals" on the BFL stuff by being entered in the contest. I loved (and still do) the Myoplex Lite bars and still use their cheaper EAS AdvantEdge Carb Control line of shakes as opposed to the Myoplex, which is supposed to be better quality but really isn't, IMO. When doing BFL, I used the Myoplex bars for snacks, not meals.
I do think it makes a difference in any bodybuilding plan if you supplement with extra good quality protein, however you do it. Just look around for good quality shakes and bars without a lot of sweeteners (no sugar). But you can also just have good meals following the pattern of BFL, clean sources of low fat protein, fruit and veggies for carbs, a little of the best kinds of fat.
A great book to learn about clean eating beyond the BFL books is Tosco Reno's "Clean Eating" ... if you can find it. A lot of good ideas there, also helps in the department of packing food, as she has a bunch of "cooler plans." A fun book.
You can absolutely do great on a Bowflex. No matter what anyone tells you, you really never have to graduate to free weights (although they are great). A Bowflex can give you everything you need to sculpt a great body (in my opinion).
Good luck, go for it. You'll do great!