lazy jacks or sail packs

Greetings all, I am looking at making a sail pack for both the mizzen and the main. I am unsure of the line spacing for the lazy jack lines to connect to the sail pack. I am thinking that just below the spreaders on each would be good. I am also thinking of 4 or 5 lines to attach to the sail pack. I was wondering if anyone could please give me a little insight into the spacing of the lines on the sail pack. For example how high on the mast? and how far from the Mast should the first line be.

Thank you for your time and consideration. I am looking forward your assistance which will be greatly appreciated!!!

Here's a picture of ours. It was made by Mack Sails. Might give you some ideas

We started with sail right stackpacks. But they were very tall and had a lot of windage. We cut them down to simple covers. I really like lazy jacks to keep things organized when dropping and raising sail.