Hello Cho,
(1)
"in the style of heavy curtains*....They are made just like unlined curtains, with the tape and pinch pleats. These would probably be considered the old fashioned type curtain swish rails and they are the ones that I used with the roller blinds. I made them myself. I bought the material in Hickeys, in Henry Street - cream voile. Now I know this is easy to say, but they are not difficult to make - if you can use or have a sewing machine. I taught myself how to sew, it's certainly not my trade
Depending on the width of your windows you will probably not need to sew any side seams. All that should be needed is to leave a few inches extra at the top of the curtain length (to make a fold behind the tape) and a few inches at the bottom for the turn up. So basically it's two rows of machine sewing to sew the tape on to each curtain length and one row of hand sewing at the turn up at the bottom of each length. If you could master the basic technique you'd save a fortune over the years. Hope I'm not not jumping to the wrong conclusion. Maybe you just haven't the time to make them.
I guess in my case necessity was the mother of invention.
I haven't used the double pole with the roller blinds, I don't want to confuddle you.
(2)
With the double rail curtains, with separate Lining and Curtain I used a plain tape just to give some stiffness to the top of the folded down voile fabric, no pleating necessary. They are made the same way, except for the different types of tape used. The lining is on rings on one rail, and the voile curtain is on rings on the second rail. I found it better not to make these curtains too full - they just sit with very little gathering when they are closed. (I was able to buy ready made linings, they were almost as cheap as buying the lining material and making them myself.) The wider the material the more rings you will need and too many rings just don't look right - in my opinion.
Btw, there was a discussion about double pole curtain rails on AAM but as I don't know how to refer on this site, try searching under "curtain panels* you should find it there.
Cheers, hope this helps.
Just sally.