Configure DNS server for "single serve IP", each request served a unique IP

Please make it so that the DNS never serves the same IP twice. Each user that goes to [login to view URL] should be served a unique IP by my BIND9 DNS master server running Ubuntu 12.04 on AWS EC2. The DNS server uses a zone file containing a list of IP addresses to serve for one host name. Currently I am running plain BIND9 via apt-get BIND9, and edit the zone files via BASH shell scripts that monitor the log file. I wish to improve upon this. Please select the best possible option considering performance, uptime, difficulty for me to implement, and your bid amount. Then use your own or my AWS account to test your solution. Email me for the login credentials. The job is documentation. The job is complete when I can reproduce all the necessary steps to make the DNS server work the way I want with nothing more than a text file from which I can copy and paste. Security is NOT important at this time. Simplicity, ease of setup, and uptime are important. ############### Possibilities: ########################### 1. Configure BIND9 to execute a script after serving an IP for the hostname. 2. Configure BIND9 to remove the IP once it has been used. 3. Rewrite and compile BIND9 to remove the IP after its been used. 4. Configure BIND9 to use a SQL DB backend, and send delete query after read. 5. Rewrite the shell script in C for performance and uptime? 6. Select a different DNS that allows for native scripting via LUA. 7. ???? ##################################################### ################Current shell script in plain english:########## Has the log file been written to? If so then, Find “[login to view URL]” in the last line of the log file? If so then, Find and remember the IP address served Find that IP address in the zone file and remove it Update Bind9 Execute [login to view URL] ####################################################################################################################################################################################################################################################