Get the mini DCT tank, with a thread cover for it. 3.5ml tank with thread cover (makes a nice line from the tank to the ego twist).
your site calls them "spacers". I don't know how much juice you go thru in a day, I don't go thru a lot, so a 3.5ml tank was good for me. I think the 6ml tanks are a bit large for the Ego Twist to be honest, it's a very "unbalanced" look to use the larger ones on a Twist.
Here's the DCTs from hyour site:
http://www.nettmixcustomvapes.com/3-5ml-dc-tank-chrome/
Spacer/Thread cover:
http://www.nettmixcustomvapes.com/3-5ml-dc-tank-spacer/
you can use the single coil cartos in them:
http://www.nettmixcustomvapes.com/dc-tank-cartomizer-1-7ohm-single-coil/
If you use higher VG juice you may want to get 3 holes. ( If you like the setup then later we can find you cheaper way to buy whole box of the flanged cartos.)
But yes, I would use single coil cartos on a twist, JMHO.
You might even want to try a mini Vivi Nova tank (like a clearo but bigger / better)/
there is also a new tank out called U-DC Tank. Here is the thread cover/base for that:
U-DCT eGo battery thread cover
and the U-DC Tank:
Smoktech SMALL ULTIMATE Dual Coil Tank (DCT)
I will ask Baditude to look in on this topic, he is like the TANK guy, has just about every kind made.......so hang in til I find him.

He will probably have better ideas than a DCT. IBTanked, etc. and some nice pyrex tanks out there, too.
Hang in there for a few......