I've posted here about what I use for a bait hive before, but briefly (hah!) I use a single national brood or two supers (when I've run out of brood boxes). Most of the (brood) frames are foundationless or just have a starter strip. As you're already familiar with David Evans' site, you can find the details for the frames there. I put one frame of skanky old comb at the back, if I have it. If you don't it's no big deal. I put a couple of drops of lemon grass oil on the top bar of that frame. Again, it's not absolutely necessary, but maybe it helps. Crown board and roof on top. The floor is a piece of solid sheet timber (or in some cases wall lining for a shower, because I had some left over and it's (obviously) waterproof, with walls 50-60mm high. Like an eke, really. In one wall there's a circular hole about 38mm in diameter (as far as I recall -- it was just a size that I had handy). I drill vertically down through the hole from the top edge of that side and then drive a nail through it to stop birds getting in.
Lots of people build bespoke swarm boxes and you can do that if you wish, but from my point of view it's just another thing to store. Having everything standard other than the floor makes my life easier.
I've put them on a shed roof where I can easily lift them down, on hive stands or even on a couple of old tyres stacked on the ground. Sometimes I try to face them roughly south, other times it's not practical. Putting them in full Sun has generally worked better for me.
Do read Seeley because it's useful information and explains where the ideas come from, but I think the most important thing is to get a space that the scout bees perceive to be of roughly the right volume. Pretty much anything else is optional. You don't have to offer them The Ritz. A Premier Inn is likely to be good enough if everywhere else they've found looks like a flophouse by comparison. Last year I caught around a dozen and a half swarms this way in a month. In a couple of instances I had two swarms trying to occupy the same bait hive at the same time.
And if you should get a swarm, put your next bait hive in the same place. If the site appeals to one swarm then there's a fair chance that it will appeal to the next.
Have enough kit ready to properly house a swarm, and ideally to treat it for varroa (because there is initially no capped brood, it's a good time to treat them). And have another bait hive ready to go too.
James