Apertrure or iPhoto on a new iMac? Photo Storage? HELP!

Question

I just purchased a new 27" iMac and before I did anything, I upgraded to Mavericks on a clean install out of the box.  My "old" computer is a first generation Intel iMac (Jan 2006) running Snow Leopard.  The internal 250GB hard drive was becoming labored with files, so I stored all of my photos, videos, and music on an external hard drive and simply directed my respective programs to look for their libraries on that hard drive. Made a MASSIVE difference on the computer and it ran wonderfully all along due to a light load on that internal drive.
Since the new iMac has a 1TB internal drive, I thought I would put everything ON the internal hard drive and just use the 1.5 TB Drive as a backup.  Importing photos to iPhoto has proved to be a rediculous nightmare with Faces and quadruplicates of pictures.  I have just dumped the whole file and want to start over from scratch. 
My question is this:  I have intentions of downloading Aperture anyways.... should I just download it and use it as my primary, by importing all pictures off my external drive into Aperture, then direct iPhoto to look at my Aperture library?  I have nearly 50,000 pictures to put on the computer so I can start to clean them out.  One of the BIGGEST complaints of iPhoto is Faces.  What a mess!  Another reason to want Aperture even more so I can disable that!  I was also thinking of just directing the libraries to look at the external again and getting ANOTHER external drive for JUST Time Machine backups.
So many choices.... don't know which way to turn.  Any advice? 
(and NO, I don't want to hear how crazy I am to have or want to import 50,000 photos..... which, with Faces and unruly duplicates became 275,000 files transfered.  Ugh.)

Answer 1

. I am leaning towards upgrading the existing library using iPhoto, then when we get REALLY bold, have Aperture look at the library........... 
Aperture has better tools to organize your photo library than iPhoto. For example, you can structure your projects (aka "events" in iPhoto) by putting related projects in a hierarchical structure of folders. And yes, you can decide, if you want to use faces, places, previews. You can delete faces, that have been created in iPhoto.
You will want to save as much of your previous work, but start with a new, clean design for your Aperture library, that will be easily mainained and suffice for many years. these goals are a bit in conflict.
If you want to eat the cake, but have it too, start your Aperture library with two folders for projects - old and new. Import the iPhoto library into the "old"  folder, and build the structure in the "new" folder according to your new design by moving items between these two folder sets. Importing the iPhoto Library will save all your edits and tags like Andy recommended, and keeping the imported projects/events in a separate folder, will help you to build a new structure from it.
These two user tips might help you decide on a design for your new Aperture library:
My little effort:                  New to Aperture? Some Considerations when Designing your First Aperture Library
And Kirby Krieger's great                  The Well-Trod Path: a Beginner's Guide to how Aperture's major parts inter-relate
After upgrading to Aperture, don't delete iPhoto in a hurry, see:
                 Keep iPhoto - It May Come in Handy!
-- Léonie