once abandonded, unless they are using it in commerce for a period of time, you should be able to either revive it or use it and regsiter it with an intent to use it.
I tried, honestly I did, but I can't make heads or tails of this advice. What does "unless they are using it in commerce for a period of time" mean?
The long and the short of it is this. If the mark has been abandoned (not merely the registration of the mark), then it should be free to use. There is some discussion -- a bit academic at points -- about "residual goodwill", but that concept can be ignored at this level of discussion.
Differing countries (and indeed differing states) have laws about using company names that have ceased to exist. You need someone local (in this case an accountant) who could advise you on obtaining the company names.
Again, not sure what WIMR_INFO is driving at, but (a) you don't need an accountant (although many handle business entity formation) and (b) most states that I've dealt with will allow remarkably close names to co-exist -- the standard is quite different from trademark use and registration.