Jehannum
Puts the "pro" in procrastination
You're a manager. Set milestones and deadlines, and take the proposal to @peanut and see if she'll agree.yeah, im really trying not to be myself and DIY this one.
Also, we need 6 heads, and that gets out of DIY range pretty quick. Apparently the multi-head systems are kinda a nightmare to work with.
A minisplit isn't rocket surgery, and at 1600 square feet, you're talking maybe 2 ton capacity (unless you're doing it in the wrong order and haven't insulated or weatherproofed yet). I'd personally do a 4 head and a 2 head, depending on how you're planning to lay out the system.
I've done a 2-head mini split on my friend's garage, it wasn't bad at all.