You can choose who ever you want for a web host. It is usually a good idea to host your domain separately from the registrar. If you end up having hosting problems it is easier to find a new host and change your nameservers.
The hosts in the above link all have auto install scripts. You will just need to consult their documentation and usually it is as easy as making a few clicks and entering an admin username and password.
Once you decide on a host and get your account set up they will give you the information you need when you change your nameservers
Go through the Getting started guide and if you run into any problems along the way come back here and we can guide you further.
Ask the most specific questions you can for a better chance of getting the answers you need.