You’ll have to make the decision between WordPress and Ghost before knowing which hosting service to go with. Ghost has a decent amount of requirements, being based on NodeJS. So with WordPress, it’ll be easy to find a shared hosting provider that provides PHP & MySQL, but finding a shared hosting provider that will allow you to run Ghost may be harder.
I do know SiteGround supports Ghost on their Cloud & Dedicated plans, but not sure about the shared hosting side. Ghost won’t run properly in a general cPanel environment, for instance. So your best bet for Ghost would be a VPS.
For WordPress, lots of good options around the forum – but I don’t see any reason that any of those options, SiteGround/Inmotion/Namecheap, wouldn’t work. SiteGround has always been fairly reliable for shared hosting, in my experience.