I'm gonna recommend you rent a camera first. I'm getting the impression that you may not like what you find.
First off, those Aero Ektar's are pretty expensive. So before you jump head first into this, it might be a good idea to do a bunch of research, and some of that should include some hands on experience. And I wouldn't worry too much about the ground glass being too dim with an Aero Ektar. If it is, you could buy a Fresnel lens to put over it. But I doubt that would be an issue. I have an Anniversary Speed Graphic and the ground glass isn't that much dimmer than any other large format camera I've used. They'll all pretty dim, which is why we use dark cloths. Knowing how to use a dark cloth (like wrapping it all the way around and giving your eyes a moment to adjust) will make a bigger difference than how bright or dim your ground glass is. So will a good loupe. In any case, you're going to find that getting a person to sit perfectly still between the moment you focus to the moment you take the picture will be really, really, really difficult. This is one reason why people usually don't shoot portraits with lenses with such wide apertures in large format. For most people 4.5-5.6 is about as wide as they'll shoot. It's not like the smaller formats where you can quickly go from setting up the shot to taking it, unless you want to have a rangefinder adapted to your camera that is calibrated to that lens. That can be done with a Speed Graphic and certain rangefinders however. But then you'll have to compose through a viewfinder and deal with parallax issues. Not only that, but at depths of field that shallow, I'd be afraid to rely on a rangefinder or distance scale alone. Or you could use an older Graflex SLR (RB Series D). But those are less portable and older. Any of those Graflex cameras will have reliability concerns. They're all pretty old at this point.
But the problem with a Speed Graphic and Graflex RB is camera shake. If you're not working with a lot of light and can't see the ground glass to well, then you're probably not working with a fast enough shutter speed to compensate for camera shake. Those focal plane shutters are heavy, and they will move a camera when you trip them. You might consider going for a Sinar with the Auto Aperture shutter accessory. It's basically a built in shutter that allows you to use barrel lenses. The downside is the Sinars are not light or easily portable. But they are more steady, and you won't have to worry about camera shake with a good tripod. They also allow for much more movements, which you might find you actually want if you're looking for such shallow "depth of field".
Or you could adapt a Packard shutter to just about any camera. Some people actually adapt them to the outside, in front of the lens (but that would take some machining skills). In any case, you're going to have to figure out what comprises you can live with, and what you actually need. And the only good way to do that is to get some first hand experience.