What is the best bluetooth choice

I want to send simple arduino data as a GPS position from
a GPS shield, some analog and digital sensor values, from
my arduino to my mobile phone over bluetooth. I also want to
be able to send it back.

I was wondering what the difference was between an arduino
bluetooth and a normal arduino with a bluetooth modem (except
that it is more expensive)

Can you recommend me any cheap bluetooth modules?

Hello,

I don't know which one is the best, but the cheapest I could find was:

But I am still learning how to connect it to the arduino (5V x 3.3V issues)