RE: top flight cessna 182
It's very, very difficult to determine how long it will take to build to completion any particular kit. The time not only depends upon how long each building session is (long sessions at a stretch get more done per hour than short ones), but what your skills are, how you like to build, how much time you spend fitting the pieces together, and what level of quality you're looking for.
Also, ask yourself this: What's the purpose in building the model? If it's for recreation, for something to help relax you, what does the amount of time actually mean? If you need to get a model in the air fast, don't bother with much of a kit.
With the Top Flite Cessna 182 Skylane, we've seen people throw one together and get it flying with under 100 hours of labor. Sure, it's no show model, and has some rough edges, but it's flyable. We've also seen models with hundreds of hours put into them that had the perfection of a Swiss watch. What do you want to get out of the project?
Sure, I'd like to be able to give you a time frame on how long it will take to build the kit, but can't. There are just too many variables involved.