Starship Troopers map. (Sorry...)

I'm working on an SST map. It's going to use a limited ammo system like the one in NOTD, and I've also removed the battlements and stone stuff from the GUI. I'm planning a map in which the Marines enter the base, find the aliens, have to fight their way to the comm tower across the alien infested wilderness, call for help, fight their way back to the base, hold out for 15 minutes, then fight their way to the ship. I'm going to include only a couple of custom models and Icons, in order to keep the filesize down, so it isn't quite like the films, it's more of a cross between Aliens and Starship troopers. I need extra ideas for types of aliens, including which model I should use (NO CUSTOM MODELS PLEASE), and more ideas for weapons/items and abilities that I can include.

Models are easy. Zerglings, hydralisks, carrion beetles, crypt lords. Creepy looking bugs that make good aliens. Arachnathids work too.

BUMP! Come on guys! I need ideas!

Eeek. Most of the time I don't start a map unless I already have enough ideas to do it alone. If you start to make a map you should have come up with enough ideas (otherwise why start making it?)

Anyway...

Well you could have a poison bullet ability (I dunno either for marines or aliens) which would be quite fun. Basically it's a shadow strike except it does practically no starting damage, then after maybe 30 seconds, it suddenly does a one-shot burst of damage. Would be fun on the players too since they'll be running around for 30 seconds knowing that if they don't get enough hp in 30 seconds they'll take fatal damage (sorta like the infestation thing you're trying to do except you can't take off shadow strike so it probably won't fit into what you're trying to do, and it's not fatal, just deadly).

And there's also a cool alien idea. You can give an alien the hydra ability and -100% vamp aura so everytime it attacks it kills itself and splits intio two versions of itself (of course everytime you attack it the same thing happens haha so this would be kinda something you have to avoid or attack only if you really need to).

And of course once the ship has landed maybe there can be a new set of abilities to make things easier like airstrike (there's a spell like that somewhere in wc3campaigns that which sends a batrider to bomb from a place. Cool ability).

Scrawler (carrion beetle model): While weak and hardly a threat in small numbers, scrawlers overwhelm the enemy with numbers alone, sometimes simply as a diversion to deplete the humans' ammo before more power creatures are sent.

Keloran (barbed arachnathid): large and scorpion-like, kelorans bloated bodies contain liquid nitrogen, which they can expel through their tail, devilvering an icy chill that impedes their victims.

Pelzer (crypt lord): Immense creatures protected by thick carapaces, pelzers are effectively a living tank. highly resistant to bullets, explosives are the way to go. Though limited to melee, they have a long reach and can tear through armor with startling ease.

Banshee (couatl): These flying, batlike creatures glide on leathery wings, striking with a barbed tail and the venom housed in its neck and head. Quick moving and hard to hit.

hope this helps. i'll post more later if i think of any.

Ooooh! NICE! I like the background!
So far I have:
Warrior: (Zergling)
Standard shock troop for the Alien Threat, limited to melee but they can inflict horrible wounds.
Stinger: (Hydralisk)
Fire bolts of an enzymatic compound that dissolves flesh and bone.
Parasite: (Spider)
Only have a melee attack, but can infest enemies and have 15% evasion due to their small size.

Edit at 4:40 pm:

Stalker: (Felhound turned black, and unit vertex triggering to make it slightly transparent)
These are nearly invisible. Their carapace isn't as armoured as a warriors, but they are harder to see. (And have evasion 75%. ^^ )
Juggernaut/Goliath: (Carrion Beetle but scaled up hugely)
These colossal beasts are heavily armoured, so explosives are your best bet, however, be careful! Parasite sacs hidden in the body burst open upon death, spreading the tiny creatures around
[Note, this is just a modification of your "Pelzer", ElvenRonin. You'll get credit for your help on the load screen/quest menu.]

More ideas

Praetor (Faceless One)- Perhaps the closest thing to a field sargeant seen to date, the praetor is the only creature that uses weapons and armor independent of its body. In addition to the enhanced intelligence, these also have the ability to psychically direct lesser minions, increasing their move and attack speeds.

I think that this map is a good idea. However, I have no ideas to give you because I don't really make maps, but I can test it for you. I would give you constructive feedback on what I liked and didn't. Don't let my reputation fool you I can be nice, the only reason it is low is because I am very open when giving opinions.