I've tried South Beach as well (although I only made it a few weeks before "falling off the wagon") and I agree the meat-intensive first couple of weeks are rather difficult. As long as you're not vegan I'd recommend eggs (or egg-beaters) as an alternative to meat. Although you may be getting sick of them if you're having eggs for breakfast as well, there are all sorts of omelette, frittata, and quiche (w/o crust)recipes out there to keep it interesting.
While I agree with FovevrBee that seitan is great, I'm not sure it's really south-beach friendly. My guess would be that anything made primarily of wheat would be forbidden for Phase I and maybe even Phase II.
Similar to bluevivor's recommendation, I've seen some "pasta" recipes where you create ribbon-like strips of zucchini using a vegetable peeler and just blanche them for 30 seconds or so in boiling water and serve with pasta sauce...maybe you could add some soy-crumbles to the sauce for added protein
One other suggestion - I've noticed they now have low-carb recipes on www.foodnetwork.com
You might be able to find some other ideas there.
Good luck! I plan on giving it another try starting next week