On another note - I have a few pairs of Sleenker, and I find them impossible to wear with anything but Chucks. With boots, one invariably ends up with the "golf club" effect - not a good look. Just my personal experience.
Hi there, have you tried Darron in 28 x 30? I find that Darron is the most similar to Belther, at least of the different cuts that I've tried.
I believe Shioner would be your best bet for an all-over streamlined silhouette.