Hi Everyone

I'm new here...
I am about to make the switch from a PC (Dell laptop, technically) to an iMac for home/personal use. I am trying to decide whether to purchase iWork and have it pre-installed on my iMac, or not. I have used Microsoft products my whole life, which means all of my archived word processing documents are .doc (MS Word) docs. I want to be able to access these, and edit them if I choose, on my iMac in the future.
I believe Pages allows you to open MS Word docs for the most part -- have you guys found this to be true? Or am I mistaken?
My real question is: does the iMac come with any kind of word processing program as a default program (other than the iWork suite), and if so, does this open .doc files? (I am thinking the answer to this is "no" but I figured I'd run it by all of you.)
Also related: If I find that Pages won't let me access and edit all of my old .doc files, I have plans to download Open Office... do any of you have experience w/ this free product?
And finally: Ideally I would *like* to move over to the iWork suite of programs for personal use, unless I hear a strong dis-recommendation for doing this. Even if Pages won't deal w/ my old files the way I want it to, do you think I should just go ahead and have iWork pre-installed right when I purchase the iMac? I am leaning in this direction, but part of me thinks it will be silly to have both iWork and Open Office on the same machine. Any thoughts on this scenario?
Any feedback on any of these questions is greatly appreciated.
Thanks in advance!
--Donna