Direct mount / bolt-on bags

My new bike is positively festooned with mounts for stuff – top tube plus three bottle cages mounts.

Looking for recommendations for small bags (tools/waterproof jacket/tube) for the top tube and under-downtube mount. I know I can use a bottle cage and caddy for that one but quite like the idea of a direct mount slot on hard case down there – rather like Topeak’s Ninja caddies. Really don’t want to have straps rubbing on the frame or risk losing a tool roll riding on rough terrain. 

Ortleib do an excellent seat pack which slots into a mount – greater for swapping between bikes – but it’s too wide to place under the downtube.