If possible, go with flyrants for your HQ. Proxy the carnifexes if you have to, but one or two of them is fantastic. I'm not sure how many termagaunts have devourers, but only a few should. Keep them in the back so that, when you lose models, it's not so bad. Hormogaunts and Stealers are meh, depending on how you lose them - termagaunts would be preferable. Venemthropes are a must, gargoyles are good if you can grab them, and troops sizes should be bigger.
How many of these models do you already have? If all of them, what else do you have? If none, how much are you willing to spend?
If you go down to the woods today, be wary