Hope you can help as this is driving me mad

SO my set up is a Tacx bushido Smart trainer, which I have been using the sufferfest app on my iPhone linked to my tv. Various reasons I wont bore you with I know want to use my pc so run the whole thing.
So I would have sufferfest running on pc which is working fine, but wont connect to bushido as it needs a dongle, fine so far.....
However I am so confused over all this, basically I want to buy a dongle that will connect my Tacx to the software and also connect my Garmin HR strap.
Could anyone advise which one I need as I keep drawing a blank and don't want to get the wrong one...
Hope someone can help before I throw the whole lot out of the window including my bike lol.....
Best wishes
Rob