Audio/Data combiner and separator

I am looking for a schematic and BOM with manufacturer name and address of a LOW cost audio and data combiner (encoder) and separator (decoder). Combiner specs Input: 1. Stereo Audio with 1V signal amplitude 30Hz to 16KHz 2. RS-232 data 2400 to 9600 baud rate Output: 1. Single signal up to 10MHz bandwidth Power supply: 1. 5V preferred. +/-5 if necessary 2. <50ma current consumption if possible --------------------------------------- Separator specs Input: 1. Single signal up to 10MHz bandwidth Output: 1. Stereo Audio with 1V signal amplitude 30Hz to 16KHz 2. RS-232 data 2400 to 9600 baud rate Power supply: 2. 5V preferred. +/-5 if necessary 3. <50ma current consumption if possible Circuit should come with detailed explanation of operation and testing. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform none, hardware design only.