We also conducted reseach as to where the best place to store images/documents.  Our orignal plan was to store the images in the file system and use Availl to replicate the images through the firewall.  We were having difficulty getting this to work properly, so opted for Plan B, storing the images in sql server.  We were using sql server replication anyway, so this solution worked.  We did begin having trouble storing images larger than 90 mb.  A support call to Microsoft helped us work through these issues.

That being said, we have finally been able to get the file replication working through he firewall and will begin using this methodology.  We will just keep pointers to the files in the database, back to plan A.