Device design agency and producer

Hi all,

I have an idea in mind for a device, componentst to build are available on AdaFruits although very expensive.
I'm looking for:

  1. An agency which could design this device
  2. For the company that could produce the entire device in small (1-100), mid (1000-10000) and large (100k+) batches depending on the popularity of the device.

I'd appreciate your thoughts and comments!

Device description:
Key features: a small 2.5"-3.0" display (OLED/TFT, no touchscreen), backed by Arduino with a BLE module, a battery power source, and perhaps some buttons or switches, frame, metal back side.
Secondary option: GPS locator (to find the device if it is lost).

Components we used for MVP are below:
Adafruit Feather M0 Bluefruit LE[ID:2995]
Lithium Ion Polymer Battery - 3.7v 500mAh[ID:1578]
Full sized breadboard[ID:239]
Premium Male/Male Jumper Wires - 20 x 6" (150mm)[ID:1957]
Tactile Switch Buttons (12mm square, 6mm tall) x 10 pack[ID:1119]
TFT FeatherWing - 2.4" 320x240 Touchscreen For All Feathers[ID:3315]

You did not identify the country you are in because customs charges will certainly impact the cost. Would you purchase all the components and just want someone to assemble the device? Would you program and test it?

I wonder how GPS would help you find the lost device? Please explain.

Paul