Loads of great advice here already. I can tell you personally that the thing we learned was that your back and your knees will thank you in so many ways when things are far more accessible. We've got an Omlet Cube with a 9 foot run, attached to a Walk In Run. It's a pain in the a$$ to have to crotch down, get on one's knees, scoop the poop, get to a hen that wants to outsmart you, etc. This is really a long-term investment. No, you don't have to spend tons of money (our Cube is a used model, only way I could afford it!), but between your accessibility and making sure it is as predator proof as possible, definitely go for the higher height. Wishing you the best!