The AAP says that infants should not get any solids for the first 6 months, and solid food doesn't really help them sleep more. If anything it can be disruptive because it's harder on their stomachs. This is a common age for him to stop sleeping through because he's really starting to discover the world around him, and he's also growing so much. Up until a year, babies still NEED to eat at night. A five-hour stretch is plenty at 5 months.
Strict scheduling is generally inadvisable for a breastfed baby, since they control how much they eat. Scheduling also doesn't respond to his hunger cues, so your supply can suffer. There's nothing wrong with routine, but scheduling isn't a good idea when you're talking about breastfeeding. Unlike with a bottle, he's able to control how much he wants, and a schedule doesn't account for things like a growth spurt, where he'll eat more.
Having him nap, go to bed, and wake up at a given time isn't a bad idea, but at this age a flexible schedule is important. If he's a little off going down for a nap or hungry earlier, you respond to that appropriately.
Check out kellymom.com for a lot of really good breastfeeding advice, too.