Welcome to ECF and to
vaping, mauisun!
Yes, e-cigars are a bit tougher to find than e-cigarettes and most of them have the whistle-tip you mention (but not all). And, I believe, they are even less popular today than in the past. I'll share my speculation about the reason for that shortly.
I am not an e-cigar vaper (nor was I a cigar smoker previously), so I can only point you to a couple places where they are available rather than comment on the pros and cons of any model. I urge you to
also post your question in the
New Members' forum (where you can start a
thread) or as a reply in an existing cigar-related
thread like
this one.
Some of the e-cigar models (and where to find them) are covered in
Part 5 of the WWV Illustrated Guide linked in my signature. Extracted from there is the one model, to my knowledge, that meets your criteria (round mouthpiece and not disposable):
However, since you are used to smoking something that is much larger than – and doesn’t look anything like – a cigarette, you may want to consider a big battery "Mod" in the same price range. [And it is the strong merits and tremendous increase in the availability of mods that, I believe, explains the decrease in e-cigar (and e-pipe) popularity.]
Mods (or "Hybrids" as I call them) are also discussed in Part 5 of that Guide (right after e-cigars and e-pipes). For appearance reasons only (i.e., they look a
little bit like a cigar), I mention two of them here:
- The $99 Spade (also available here). Not the most powerful of the Mods, but one of the sleekest.
- The $75 Chuck and Little Chuck can be customized to look like anything (at least of that shape). Since each is unique, it is difficult to present a representative photo. Ironically, of the scores of example photos on Jeff's website, it seems no one (yet) has asked him to make it look like a cigar. This is the closest that I found:
It is fatter than the Spade, but much more powerful and, according to a poll I saw recently, it currently is the most popular commercially available mod. Here are just two of the many reviews (of the Chuck and of the Little Chuck):
YouTube - The Chuck Review
YouTube - Little Chuck Review
Find out more in the
CHUCKleheads forum and social group. [NOTE: That is not a derrogatory term I came up with, but what they call themselves.

]
But remember, those are only two of the
dozens of mods currently available.
Have fun learning about all the possibilities, mauisun!