Munton's is junk, but their Munton's Gold might work for "all malt beers" according to their website. Even Munton's doesn't recommend their regular strain for beers that don't use corn sugar!
Coopers is also junk, at least the couple that I"ve used. Throw it away if it comes with your kit!
A good quality dry yeast is important. I like Safale (So4 and S05) and Nottingham (Danstar) for ales. I've never used a dry lager yeast, so I don't know about them.