Easiest Bluetooth addon for 1284P at 3v

Projects General Guidance
1

Hi,
I have a working project using the Crossroads 1284p running at 3v3 to measure various temp and pressure sensors. I'd like to do the following and am seeking recommendations on which Bluetooth setup would be best, i.e. easiest to incorporate,

Functional goals:

  1. Remotely Upload new sketches
  2. Remotely Interact via serial terminal
  3. Supports Android Bluetooth connection to eventually develop an app to send serial data (1284 rcv using Serial parsing) and receive serial data for display in the Android app.
  4. if not already obvious, connects via 1284p Serial TX/RX at 3v3

Thank you,

2

There is a 3.3v Board with HC-06 and also a dual-voltage HC-05, but I don't know how easily they are found. It may be easier to modify a standard 5v board by simply bypassing the on-board regulator.
Bare HC-05 modules are on eBay, but installing one is probably rather tedious.