From what I've read on forgers through the years, the $40 400w fog machines aren't exactly amazing and lucky to run more than one season with A LOT of maintenance in between. Although what does help any fog machine is using more expensive, brand name fog juices. Froggy's I believe is a favourite of many, but don't take my word for it.
Because of the push distance your talking about, potentially 8ft, I imagine an extra fan to help push/pull the fog up to and through the nostrils, snout or mouth would be a benefit. Especially if you want intervalled pulses.
I would guess your gonna need a large fog tank to keep up with the constant pulsing. With that, have you looked into vegetable glycerine? Its an ingredient in ejuice for nicotine vapes of the modern world to give the clouds some density. Mixed with food grade propylene glycol to allow for some wicking and ease of flow through cotton. Though I wouldn't use it in a store bought fogger.

The further I type the more I realize this is way outside my wheelhouse, good luck on your venture!

 

1) A fogger with a timer.
2) 2 inch automotive duct hose
3) 2 inch in line duct fan.
I would suggest a few weep hole drilled into the bottom of the hot at its lowest point to allow for condensed fog juice to escape.