Either tower will work, but it's either death by tentacle or death by self-immolation when going through each tower.

If you decide to fight through the western tower first, skip to that section first (you will start with poison zombies 5 through 8). If you need to upgrade your weapons and such, there is an enemy free bench in the western grwoth tower. Lucky for Isaac he has that breathing mask eh? The save room with the red alarm is totally safe (there are no enemies here), so use that as your base of operations to attack the four poisonous zombies in the east and west greenhouses. There is a schematic for the Contact Gun ammo in the small room right before you meet the ailing Hammond. If you aren't going to use any, you might as well sell them all for the credits. However, you will occasionally earn ammo for weapons you do not own from footlockers and lockers. If you aren't carrying a weapon (even if you own it but have it stored), enemies will rarely (almost never) drop ammo for it. If you've only been relying on the plasma cutter and linegun, your ammo drops will be totally focused on those weapons and you should have very little problems (just don't miss). This stage can take a toll on your ammunition stock, no thanks to the ambushes you have to deal with, the brute, and the numerous enemies in the stage.

Dead space chapter 6 boss