Does anyone know if you can upgrade ASA 5505 from 8.0.4 directly to 18.104.22.168? Concered of going from 8.0 to 8.2 train.
Yes, you can go directly from 8.0.4 to 22.214.171.124.
One thing to be aware of is the memory that you have for the ASA5505. It is recommended to have DRAM of 512MB if you are upgrading to version 8.2.2 or above (especially if you have unlimited host license and/or security plus license with failover). For version 8.3, you are required to have 512MB DRAM for ASA5505 with unlimited host license, and/or security plus license with failover.
Here is the release notes for both 8.2.x and 8.3.x:
Hope that helps.