Hi Calum. I have stayed at both the Corona and Tortosa Parc. Corona is more modern and has a pool, ( abit early to use it) It is on the outskirts so abit of a walk into town. I asked for a 'mountain view' and I got it ( better than looking over the road) Try asking for a pool view and you will not be looking over the road.
The Tortosa parc is more basic but it was clean and friendly and I got a good breakfast. No Pool of course and it is cheaper.
The TORTOSA PARC is right opposite the parc and near all the shops, market, river, cafes etc. It is definately better situated.
I have also stayed at the Hotel Miralles in Horta de sant Joan. Probably abit far out but it was a really nice hotel and the food was very good too.
You can book over the internet if you do a google and find their web pages, I did that and paid before I went and they were then expecting me!
There is also the lovely Parador, 4 star hotel with stunning views. I walked up to it to take in the views and wished that I had the money to stay there! IF  you can afford it this is the place to stay.
Have a great time!
P.S. one thing I found is that if you arrive at the train station in Tortosa there is no Taxi rank so you will need to ring for a taxi, you could ask the chap at the station or I can give you a couple of numbers that I have kept in my 'spain' wallet