A LW with a split reverse needs a double sole or else the proportion will be off. If you really want a single sole, then I would suggest doing a flat welt. I can see a LWB split reverse with single sole working with suede. But why would you be afraid of the bulk? IMHO, the "bulk" is part of what gives a LWB it's character. That's why we call them gunboats, right? If I want a streamlined shoe, then I'll get a balmoral.