visually sort ordering “custom post types” for end users

Now with those custom post types and other bits of content that
don’t necessarily need to be organized chronologically by date, for
example: the client has a 100 T-Shirts as custom post type “SHIRT” and
he wants to set their appearance order.

What approach you suggest taking for letting the editor/admin of the
site SORT their order?

I might suggest these:

http://drewgourley.com/order-up-custom-ordering-for-wordpress/