white is meant to be better to begin with as wholemeal/brown is too fibrous and might bung them up. I make my own bread with a breadmaker so I don't worry about how much salt DS eats. <looks for medal>
bread does have salt in but it's one of those things you can't really avoid unless you make your own.
i just try to avoid most ready made stuff, i don't add salt when i cook, nuts (except for almonds - they are sodium free), ham/bacon/salami/pepperoni etc and we don't eat much bread, cheese or eggs. i buy both unsalted butter (for cooking and sandwiches cos you can't taste it) and salted butter (for putting on plain bread/toast)
I've started making my own bread in anticipation of LO weaning in the next few weeks. We don't eat loads of it, so it's not that much of a faff to do once a week. It's actually really easy, even without a bread machine. I use this Delia recipe and cut the salt in half to 1tsp. I also grease the non-stick tin with olive oil instead of butter. I find it makes one good medium-sized loaf, rather than two small ones.
And, it's tasty! A good crust on it and nice and dense, but not too heavy. I'm hoping DS enjoys it once we get going on bread.