If you DO decide to switch from PHP to Ruby on Rails make sure to get very familiar with Ruby before you dive into Rails, otherwise learning rails will be very frustrating. You can also try out Sinatra before Rails. Sinatra is a great lightweight framework that I've been using extensively. It is awesome. http://www.sinatrarb.com/

Regarding whether or not to switch I will say this: you can build whatever you want with either language. The big reason you should switch is the fun and challenge of learning something new. Both languages/frameworks have their advantages and disadvantages. You will be LESS productive if you switch languages at first because you will be new and will have to learn the 'ruby way of doing things'. Eventually you may end up more productive in the long run, but productivity is influenced by so many factors and language/framework is just one of them.

Regarding deployment, Heroku (free for small apps) is a good option for if you don't want to deal with deployment much. Linode ($20/mo minimum) is great if you need to do anything fancy and/or want to have root access to your deployment environment.

http://railstutorial.org is the best rails tutorial I've seen

Good Luck!