Copper to PEX for future remodel

SO I searched around a bit but this is a pretty unique question I think.

I'm remodeling a mainfloor bath over an unfinished basement. I plan on putting in a bath directly below in the basement down the line a few years when I finish out the basement. At that point I will also replace all the galvanized supply lines with PEX. I'm also going to put in a hydronic radiant floor heating system either this summer or next.

The question is: What is the best way to plumb my new bath fixtures into the existing galvanized so that I am ready to hook in to the pex system down the line?

I was thinking of doing copper from the valves down to the joist space and hooking a short run of pex over to the galvanized. When I tear out all the galvanized I will lose the short runs of pex and replace them with the full runs of pex to the manifold. That way I dont have to buy and sweat a bunch of copper I'll end up tearing out down the line, just a bit of pex.

My concern with running pex all the way to the valves in the bath is that when I do the rest of the plumbing I will have to connect pex to pex instead of that copper to pex. Does it matter?

Did I explain it well enough?

Thanks for your thoughts!

There is nothing wrong with connecting pex to pex - it is done all the time. Since you are planning to move to a pex system in the future, I don't see any benefit to running copper now. I would run whatever pex you plan to run now, and finish replacing the rest with pex when appropriate.

Ok, thanks for the quick reply. I just thought you didnt want to have any couplings in the pex except for at the manifold and at the fixture. I will worry less.