if you want very smooth porridge maybe you can try to cook the porridge first then press it over a sieve. it will make very smooth porridge. i make before but only once.. too much work i feel.. then i simply give my girl normal cooked porridge. since she takes it i dont bother to do extra job hehe.
for brown rice, yes, it can be serve as a normal porridge but then ppl say its heaty... i give my girl brown rice but then only maybe 1-2 times a week. usually mix into her white rice porridge. very very seldom i give her brown rice porridge itself...
i just buy any adult brown rice from supermarket..
for what food you can feed at 7mths, you can check out this site.. Healthy Homemade Baby Food Recipes, Make your baby homemade baby food with our easy baby food recipes, solid food tips, baby nutrition & more!