Basically, for off-the-shelf, easy to buy in the US, your choices are fairly limited but there is more now than a year ago
Yes, I own all of these, except the DB2, which I used to own but pif'd to a friend
On the very inexpensive side, single battery, you have Kanger's Dripbox 2, or Hcigar's Vt75 Inbox or the Wraith. Wraith falls apart quickly. Between the first two, I personally prefer the Inbox - just because it's super easy to use. The side squonk doesn't bother me, but some prefer front squonk. I just don't care for how fidgety the kanger chip is. The one I have likes to try to jump into TC mode, which I do not use.
For double battery squonkers, you have the Kanger 160, the Geekvape Gbox or the Lost Vape Drone.
Of those three, I like the Geekvape best - once again, just easier to use over the Kanger. They use the same bottles and the bottles are positioned almost exactly the same. Not a big fan of the Drone - the position of the squonk bottle is inadequate and the stock bottle seriously blows for such a not-so-cheap mod. The chip in it rocks though, lol
There are a few other regulated squonks available direct from the modders or that have been long discontinued (Halcyon, Steam Crave and VaporFlask) so not really worth mentioning.
As for bf atties, I'd recommend looking at what you are vaping now and see what is similar or if what you already like is friendly to being squonkified
You can look to Europe and/or FB for other regulated squonkers that are not readily available off the shelf, and few are affordable. And for the record, I can't give them a thumbs up or down, because don't own any nor have I ever vaped any of them