Selecting audio input/output

I have been looking for this over the entire interwebs and i can't find a answer.

So i have resorted to asking you guys!

I am a motorcycle rider, and i love to lisen to musik while riding, using a set off earbuds(I think that is the right word)

One off the problems is that if i recive a call i have a big problem, there is no easy way to answer it while riding.

So i bought myself a Nokia BH-608 bluetooth headsett, I has a simple micophone on a cable and a earbud, but most importantly a answer call button.

So when i tested the setup, with the earbuds conected thru the 3.5mm audio jack, and the bluetooth headsett.
I recive a call, i am able to answer the call with the button,
But the problem is that the call audio is sendt to the 3.5mm audio, and it uses the buildin mic, that don't work because the phone is in my pocked and usualy traveling at 100km/h.

So i changed it to use the bluetooth headsett, that way it uses the bluetooh mic, but also the bluetooth earbud, but it is WAY to weak to be heard.

So i need an setting or an app that enables me to frely change the inputs/outpust for calls.
So i can select the 3.5mm jack as call audio out
and the bluetooth mic as input. :cool:

It would also be nice to use voice comands.

Ooh and yeah... I'm using a HTC sensation 4G, running Android Revolution HD 3.0.1

Sorry for writing so much unessasary info XD

Thanks :)