I tried watershoes but that didn't cut it for me, dunno why, then sandals (Teva) worked, but too light, now I wear a pair of Underarmour shoes. These work better because I like the added weight of a shoe combined with the flat bottom. Sorry, no pics. I used to play barefoot, but found that wearing shoes added weight I needed, but just like you, I couldn't do heel-toe with them on. I wear a monstrous size 15 shoe, so as you can imagine, it wasn't easy with a regular length board. But a sandal works well because I can go a few sizes smaller and just have my toes hang over the top. Plus, totally flat on the bottom. I am still thinking on going longboard due my big feet. But try sandals....
Gretsch Maple Renown, Cherry Burst
Vic Firth 7A