Yes because the PS3's output can reach up to 1080p you will need a full HD television to get the maximum output of you playstation 3, and trust me you will notice a huge different to your current gaming graphics. You can be look at £500++ ($950++) for a full HD television.

I have played Pro Evo 2008 on both the playstation 3 and xbox 360 and have had neither problems on graphics nor gameplay.

Hope this helped.