VanCough
Environmentalist
They're all mighty pretty pieces, but think all are going to create quite a bit of diffusion. Diffusion has little to do with the size (other than churning in a tube), and more to do with percs and path. I'd strongly suggest you get a simpler piece for vaping. They're cheaper, too! Maybe not as intricate, or cool looking, but the fewer tiny bubbles churning around in there - the better - IMO.
Matrix type percs (sometimes tires and other names) can do this pretty easily, but IME take a little more hit control. Slow and steady until clear is fine. But the simpler showerheads (D-020 & D-020D type) work nicely. One of my personal favs for simple low diffusion vapor is the good old FC ufo. It doesn't look like much, and is almost corny with tube option (which I enjoy regularly by the way), but is a solid hitter and you can orient the mouthpiece whichever way you like.
Stick with reliable sellers who have a good rep here on FC as always.
EDIT: @CroZure - I'm not exactly sure what you are saying with the "deep" pull, but if I'm getting it at all, it's what I would call initial draw resistance. That can be fun for me sometimes, and I really like it on dabs. For a couple cool pieces that do this, while still somehow retaining flavor, check out the FC710 and good old D-cycler (also available with a honey bucket from same seller). They're also 14mm male, which from what I understand will work well with your GH.
I would respectfully disagree, all of the pieces I linked have simple percs that will not produce loads of bubbles.
Also, diffusion is definitely linked to volume of pathway which is why the ones I've linked would be good because they have low volume to keep the vapour dense.
At the end of the day it's personal preference, and even though it's cheap glass I'd still have to like using and looking at a piece.