Hi Guys

I am new here so hope this is in the right spot. I am looking at making a move into FF (currently use a 40D) - actually thinking of shooting 2 cameras 5D for wide and normal and 40D for tele as I am sick of missing shots changing lenses etc and would appreciate the improved image quality/better low light performance and crop flexibility of the FF.

Unfortunately I can't afford a 5D MkII so am considering trying to buy a used 5D instead. A couple of questions you might be able to help with:

- am I crazy to buy a 5D classic "old technolgy" etc;

- where should I look for decent second hand cameras (ebay aside);

- any tips on how to know if one is in good shape (other than obvious look and feel) as given they are semi-pro often they have seen heaps of use;

- anyone have experience shotting a FF/Crop combo and does it work well?

Thanks so much for your ideas.
Cheers
Josh