I would like to hire a Circuit Designer

Circuit design I have designed a circuit that I know works because I have tested it extensively on persons in a wired headphone situation (hand-soldered by DIP), but I need someone to help take us to the next step - wirelessness, more current, and SMD. Background… tDCS and tACS both inject current into the body, the former uses direct current while the latter uses alternating current at (usually) adjustable frequencies. We want to be able to control the frequency of stimulation sent into the body because some frequencies enter people’s bodies better than others. What we are aiming for is adjustable tACS that can be controlled from a cell phone app, inside a device that can also play music. Circuit specifications: Wireless (bluetooth, i.e. smartphone compatible) Two outputs to speakers that play audio. The device can act as traditional bluetooth headphones. Adjustable volume for listening. This volume adjustment can be done in software. Two outputs that inject alternating current into the body. Adjustable power for stimulation. There should be hardware buttons for making these adjustments (digital potentiometer). The device can eject adjustable amounts of current over a 15 kOhm load. The current amount should be an adjustable range from 0mA (device is music-only) to at least 0.3 mA, but not more than 1.1 mA. So ideally, we would max out at something like 12 Volts (12/15,000 = 0.8 mA). Stimulation is performed over two electrodes attached to the skin on the left and right sides of the head. The current should be able to run from either left to right or right to left. I.e., it is alternating current… One input that receives current from the body, for recording bodily electrical responses… Not a huge deal if it can’t be done. Rechargable from microUSB I have done enough research into this project to know what is likely needed, although you're free to suggest your own approach: A bluetooth module (2.1 likely) A 3.7V Lithium Ion battery (likely 100mAh or less). A microUSB charging module A boost converter (3.7V input, 9-12 V output ideally ) An op-amp A digital potentiometer (two buttons on the device control voltage output from the op-amp) Soldering marks on the PCB for attaching headphones, electrodes, and a battery. I have deliberately left out some details that may make this task easier. Looking forward to hearing from you!