What makes you happy ?

I’m after advice.

10,000 images.
On Windows they are in the main tagged, are certainly in folders and between the tags and folder names single images are pretty easy to find. What would you do to get them into the Mac?

So far I see:
- an image viewer that does not tag but is a good image viewer.
or
- iPhoto + keyword assistant and start from scratch
or
- spend a lot of money for something like iview which comes with many more features than I’d need.

Ideally I’d have an image viewer for many tasks and something a bit heavier for the organising. I don’t think or expect 1 app to do the whole lot.

Retagging all the images is one task, re-organising them to how they are stored right now is another. I can see that if I worked through every image and both tagged and stored them that I could have a very good system. But I don’t want perfection, just a level of workability that I have on Windows. I’m not even tied to the absolute file system I have on Win but there would need to be an advantage to changing it. Does iPhoto have some hidden setting where it fully respects the current organisation? Is this something a Win > Mac user will find tricky no matter what software?

Back to the problem.
So, what would you do?

[....several hours later and I think I've got an answer. But it's 00:33 so I've no more time to play today..]