Bladebound magus gets a magic sword, which is an intelligent item, so you get your own sword friend who's their own character, their stats progress as your level does and they have fairly high intelligence and some magic skills
Eldritch scion magus gets to cast with charisma instead of intelligence, gets a short list of spells known instead of a spell book but can cast them more often.
unfortunately both of these archetypes change how arcane pool works so you can't have both per the rules, but both add restrictions that don't conflict and you get a couple of new ways to spend a very limited resource so you can't do anything too wacky with it.
but if the GM lets you you can play a complete bimbo who's all charisma and strength and has their talking sword to read magic texts for them
you can take bladebound and staff magus though, which lets you use staves one handed, if you want the Gandalf loadout