Whatever works for you is the right answer.
For me, I finally found that the best 60% was already available as the HHKB Pro 2. Before actually trying it, I thought I would not like the Backspace above the Return/Enter and that I would miss dedicated arrow keys. After trying it, I adjusted almost immediately, and now I remap all my other keyboards to as close to the HHKB/Mac layout as possible.
In general, the standard layout of the lower right corner with such a long Right Shift is crying out for modification. I use Right Shift a lot, but I don't need anything nearly as large as the standard Right Shift; 1x is too small, but 1.25x or larger is fine. I like the idea of shortening the Right Shift and putting Fn next to it. However, if you absolutely want dedicated arrow keys, then putting an arrow key to the right of Right Shift is fine as well.