The type of hosting you need really depends on the amount of traffic your site gets. If your site is well established and gets thousands of visits a days then you should look at a dedicated server. For most small to medium enterprises shared hosting is fine. Try to find a hosting company with UK located servers if your primary target is UK traffic, this will reduce page load time. I would recommend either Pixel internet or Heart internet, both have UK servers, great up time, and offer hosting for around the £30 per year mark.