I'm using the only brown rice they have in Japan - and it's simply called "genmai", which means "brown rice", lmao. It's quite short grained, and not nearly as nutty as I'd like it, but you take what you can get ... it cooks fairly quickly - 30 mins or so.
You're right, the lentils go mushy if you cook them too long (which is great if you're making dhal). Just add them a bit later. This also depends on they type of lentils one is using, though - some of them take longer. Enjoy!