talk me through this backup idea

Lovin the MKIII. I need a backup though. I originally thought 5D, but that was contingent upon 5DII being released and prices dropping to $1400 or so. Well that didn't happen. Here are my ideas

1. 30D
+ 1.6 crop for more pixels on target
+ Cheapish
- Still won't have an ultra wide

2. 5D
+IQ
+FF
+Have an ultrawide
-Expensive

3. 20D
+Really Cheap
= Is the 30D that much better? Hmmm I did sell a 20D for a 30D

If I buy a 30D I'll prob buy a sigma 10-20 or a 12-24 to use on the MKIII

4. 40D
= Is this really that much better (aka $300) than the 30D?

Jsut so you know your Gear List link links to someone else.

What glass do you have already?

Oh and uh...5D . The giant viewfinder is a joy to shoot through, and IQ is unbelievable - completely worth it!