Most competent web designers should be able to provide any level of deliverables. If all you need is Photoshop because you can handle the HTML/CSS in house, as

Most competent web designers should be able to provide any level of deliverables. If all you need is Photoshop because you can handle the HTML/CSS in house, ask for that. Should save you some money. On the other hand my experience is that if they can't provide you with the HTML/CSS, skip them. It takes some understanding of markup in order to design a good web site. I've worked with too many designers that do mainly print work who decide to try out their skills on the web. Usually leads to a poor result.