I had my doubts when I ordered the XL CE2's, and I know you said least fiddle but, once you spend a few minutes with each one they are awesome. Hold almost 2ml.
If you do decide to change your mind and fiddle a little, order two packs of five, until I learned to get them working the easy way, I damn near destroyed the first one. Took one apart last night and cleaned it, slapped it together after a dry burn and works like magic. I can see these lasting a long time.
For a big
tank I've heard good things about the Chibi, but I don't like cartos as much as the CE2.