If you want to stick with a TLR go with the 'cord. Otherwise, go with a Hasselblad 500C/M. Its much more versitile, if slightly more complex. They also have 645 backs for it. If you get a 645 only camera, you'll always be wanting that 6x6 option... I have a 124G like you did, and got the Hassy on a spur of the moment decision. It's now my favorite camera, which makes my F6 very sad.
And with regards to the above post... I LOVE the sound of the Hassy shutter
To each their own, but you need to find out what your own is.
A benefit of the Hassy is you can focus much closer, and the viewfinder is extremely bright even with f/4 lenses. Compared to the Yashica WLF, there is no comparison...