I added a digital one from an X5 to my 5 series, you'll also need a harness adapter which basically adds the TV module into the loom between the tuner and the nav computer. It's plug and play except you need to move a couple of pins from the existing tuner plug into the new one that goes in the back of the tuner
The issue is that in a BMW the tuner is a separate module in the boot where the nav computer and TV module go. In the Mini the tuner is part of the head unit and the nav computer is under the seat, so you probably need the same harness I have from my 5 series except it would need to be longer and routed up to the stereo.
My harness was a BMW part sourced from the dealer so I imagine a Mini equivalent is available also. You also need an antenna as your car (probably, can't say I've checked mine) won't have the antenna in the glass like a car with factory TV would have done.
As I said I did all this in my 5 series and I'm not doing it in my Mini - what does that tell you? You can get a TV in motion hacked module, but the reception is so bad that it isn't worth it. All I ever used mine for was if I waited in the car while my wife was shopping or something; depending where I parked I might get a watchable signal on some channels.
In terms of Bluetooth you can buy a complete kit from BMW Bluetooth Retrofit Information, or you can get the bits separately (but I don't know what they are beyond you need a ULF module and some sort of harness to plug in to the car wiring). I didn't get as far as doing this in my 5 series, but I have just fitted the MFSW controls with phone buttons (my car is an early facelift that only had stereo ones before) ready to fit one. I just need to check if the new iPhone 3G works with it as I'm planning to pick one of them up on Friday.
You will have a bigger job if your car has no MFSW or if it's a pre-facelift, and in any case it seems you need to cut the headlining for the mic. I may end up just getting the interface between the MFSW buttons and the Parrot my car already has from Mikey.