Tools, Sharpening and Power Machinery - Nailer Question

For a first time project, I'm building a 10x12' tool shed, the foundation and framing is almost done - next is the roof. My next project will be a couple of additions on the house.

Based on the nailing I've done, I'm thinking that a nailer would be useful and quicker. Can someone give me an overview of nailers? From what I can tell, you need different nailers for framing, finishing, roofing, etc., right? Is there a general multi-purpose nailer? Or one that could do two things, such as framing & finishing or finishing & roofing?

Also, what brands to look for or avoid?

Thanks!
Bob

finishing, roofing, and framing all require different nailers.

and the profressional roofers around here dont even use roofing nailers.