I've hated the Sumo strap gap for years and felt resigned to the zulu/nato when I didn't want to wear a bracelet. Seems I wasn't the only one and Crafter Blue of Hong Kong (I've got no affiliation with them) designed and manufactured this dedicated Sumo rubber strap with a brushed stainless keeper. The strap comes in three colors, black, blue and orange, is about 5mm thick, doesn't seem to be a lint magnet and is comfortable (for me) to wear. Also, it's not as long a strap as an iso so there's not an excessive tail for normal sized wrists (mine is about 7 1/4 inch). However, if your wrist is larger than 8 inches this strap might be a little short for you. This quality strap costs about $65, comes with a year warranty and the customer service is great.
The strap is flexible but not too flexible like some silicon straps and the end link area feels very solid.
I've really cinched it down in this shot and have about 6 holes left of 14