any biomorph that is listed in the codex has a purpose. do not forget that.
any biomorph can be of good use in the right circumstance. because MEQ armies are the most prevalent, adrenal glands on hormagaunts are not a bad decision. you get the same punch against MEQ units while using adrenal glands to upgrade the WS of the hormagaunt as you do using toxin sacs, but adrenal glands are cheaper.
having the adrenal gland to raise initiative, you get the ability to attack first, which is even better.
toxin sacs allow you to get into CC with light vehicles (AV10) and have a chance of killing them, so they are not entirely useless.
enhanced carapace allows you to take 1/6 less casualties in CC, but weigh that against the cost. would it be better to take more for the same cost?
flesh hooks have their uses too. they allow you to take advantage of the ability to move through impassible terrain, which is invaluable in a cityfight. also, if you know your opponants will be in cover, then this allows you to strike at the same time as them, which can increase the surviveability of the unit immensely.
and so far i have only covered the biomorphs for just hormagaunts.
there is a huge amount of possible combinations that a carnifex can be configured to. not all will be effective in the situation that you put your fex into, but they all have a purpose. you need to identify what you want your fex to be able to accomplish, and tailor its biomorphs to be successful. this goes for all nids. that is how you can become successful with nids.
anyways, to critique your ideas.
if you want plain stealers, go for plain stealers. flesh hooks can be useful, as can scything talons, toxin sacs, extended carapace, and feeder tendrils if put in the right situation. they are still deadly while plain, but less specialized.
the warriors should definately be given leaping or wings if you give them a CC role. toxin sacs are not needed in most cases (although i take them anyways), but adrenal glands (I) are very useful on CC warriors. you may want to toss in a lash whip. they are incredibly useful against units like terminators, and doesnt affect your combat effectiveness too much.
as for the gaunts, if you only have a small number of them, devilgaunts are the way to go IMO (devourer and if you like toxin sacs). an addition to this to make it devastating against GEQ is to give it adrenal glands (+WS). its cheap and it increases the amount you kill by a lot in combat, and it is very surprising to your opponant.
for the hormagaunts, i'd suggest giving them adrenal glands (+I) because they are useful against MEQ units. if you really want to you could give them toxin sacs, or adrenal glands (+WS), but it really starts to increase the cost of them. you need to take them in numbers, they will not match up to a SM when they both cost 15 pts each.
for the fex, you definately need some ranged support. a dakkafex or sniperfex is what i'd suggest. alternatively, for a small game you could use a TLBS fex, because in most small games your opponant will take lots of infantry, and a TLBS fex is very effective against infantry. i'd still suggest a dakkafex or sniperfex however, because they are much more universal (and a dakkafex can count as elite in a 1500 pt army).
i would also suggest you pick up a second battleforce. they are very cost effective for most people who play nids. if you are sure about going nidzilla or swarm style, these are not the greatest choices, but at least you'd still have some variety for the odd friendly game.
and for wings for the warriors, i used dragon wings (back when you could purchase individually) and pinned them (with the help of greenstuff) to the middle of the torso. i put the weapons on the upper and lower limbs, and i put the warrior on a flying base. they dont have any legs because of this.
and in a battleforce, you can actually squeeze out a fairly large army. you can definately get more than 500 pts. the fex will cost more than 100 pts, the warriors will cost about 100. the hormagaunts will cost a little less than 100, the gaunts (if you use them as devilgaunts) will cost 100 pts, and the stealers will cost over 100 pts. thats closer to 600 pts than 500.
i hope this helps.
