This collection of patterns is just adorbs. I am a sucker for knitted trousers, but adding those stripes - I think I am going to have to knit my own. We also get regular requests in the shop for hooded tops for small ones. This would is a great pattern and is available up to 24 months (King Cole generally size generously too so if your 2 year old is particularly small you might get a little more time out of it!)
Knitted in King Cole Big Value Baby Chunky, a washable and supersoft yarn perfect for babies. You could also try King Cole Drifter Subtle chunky for these patterns as it is a lightly marled yarn that is soft and squishy (and also machine washable).
You will need 5.5mm and 6mm needles for these projects. The pattern recommends a 5.5mm circular needle for the hoodie - which you might as well use for the parts you are knitting flat rather than buying two needles!