Any models that accommodate sitting down? No experience with prostate massagers/plugs.

I’ve been lurking in this sub for a while and want to finally get around to buying an aneros prostate massager. I’ve been recently looking into the MGX and Helix trident but they don’t look all that comfortable during the seated position.

I also read around in the sub that people actually clip the forks that remain outside your body, so I’d rather buy the right toy from the get go.

I have three questions:

1. Are there any aneros massagers that can be used whilst sitting down (i.e. on a desk chair)

2. What position do you usually use for your Aneros trident massagers? Do you lay down on your belly, or..?

3. I’m a 5ft 5in male so quite short. Do I need a smaller device or are the toys a one-size-fits-all solution?