How to fill baby up for bed without rice cereal.

I am stating this first because people will jump down my throat about it my baby is 4 months but is considered advanced for his and his doctor recommends starting solids. I read about rice cereal and don't really want to do the rice cereal, however my baby doesn't sleep well through the night he still gets up 3 to 4 times a night. Is there a better alternative to rice cereal that is more nutritional? Is oatmeal better then rice cereal please help!!