Special bitcoin node I was thinking of hosting my own node. I have a fast Amazon AWS server, however not enough storage to host a full node. What I was thinking, is to host a full node on the AWS client, but get it to store and write to a blockchain on a different database server, where storage is cheaper.

Is this possible? Or is this not classified as a full node?
If you are running bitcoind on a VPS it will expect the blockchain to be stored on the local disk.  You could setup a remote file system using NFS or SMB but this will probably slow down the node and make it less responsive.  Amazon already has one of the cheapest cost's for storage why not just increase the size of the drive?  If you are talking about moving the blockchain from disk and storing it in a database that cannot be done without modifying the bitcoin source code.