If the gym if full of so called "roid afficionados" by which i assume you mean big mofo's, then chances are there is good kit there for training, because no matter how high their roid expertise, they still gotta be lifting some weight.
So many non-problems in your post. If you only need the gym for 4 weeks then use any gym where you can pay and go. Dont judge gyms that dont have ipod docks on everything and nice shiny paint jobs because many of the best gyms are the spit and sawdust root gyms that are all about hard work not poncy yuppies admiring their hair between humping medicine balls.
Try something new you might find the gym full of 'roiders' is actually a really interesting place to train.
This, I'd love it if there was a decent gym like that round here.