I dont know what Audiology is, but all of the major DAW's have tons of free plugins available. Cubase, Reaper, Protools, Garageband, any modern DAW will have free plugins available for every fx in the book. Comps, reverbs, delays, autotuners, you name it. Use them. Protools uses RTAS plugin format, pretty much everything else uses the opensource VST plugins. Get any DAW that can do VST's, and you'll have so many free plugins available than you won't even be able to try em all.
About getting an interface with compression/fx... Not to get too off track here, but it's worth mentioning: The ONLY thing onboard interface comression/fx are good for is letting the musicians hear nice compression/reverb/whatever while they're tracking. But it should only be in their headphones, NOT your recorded tracks. I call it 'comfort fx' - because the musicians feel more confident and actually perform better if you have their headphone mix nice. If they hear their own raw dry voice, they think you're a quack and won't try as hard, they don't see that vision of the final product cuz the mix is so far off.. Just make sure you aren't recording the fx. Most interfaces with fx have a pre/post switch that says if the fx get sent to the DAW or not, but will send the fx to the mains/CR outputs regardless. That's what you want. The reason is, if you record the compression, you can't un-compress it later if you put it on too thick, or otherwise don't like it. Record all tracks dry, NO fx, NO EXCEPTIONS! At least not until you are so familiar with the process, that you know why you should be recording fx.
The short version:
1: Get a VST capable DAW, and a compatible interface (just about all are)
2: Record dry tracks. If you can give performers comp/fx without recording the comp/fx, all the better.
3: Use plugins to add fx later during mixdown.