We do it a couple different ways. At our events we "project" to three Mac computers using a Linksys router from our main IMac..I don't believe it makes a difference if its Mac or PC. We have proprietary software for the search capabilities..we shoot horse events and all horses are grouped by the number they wear.
In our studio we use Preevu to sort and select images, only full resolution images, jpegs, are projected. We use a Mac laptop that contains the Preevu software, run it through Apple TV and then into the LED tv. What is key here is the Preevu (or ProSelect) software. Allows us to project an image or group of images that are actually on the clients wall...we have them send us a jpeg image, even a phone image is okay. Preevu allows us to build a group, add frames and have the clients see it on their walls.
We don't sell anything under 16x20 for wall portraits..it becomes very obvious to a client that an 8x10 is not a wall sized portrait. All of our portraits are "unveiled" at a separate session and all are framed. We do give the client the option of purchasing an 8x10 unframed but only if they have purchased the same image as a wall portrait.
Here's what happened:
We invested about $2,000 in a sales room furnishings and the tv. Our portrait sales have gone from $400-500 per session to upwards of $2,500. People can't visualize anything larger than an 8x10 and have been trained that that is a large sized image. Our process educates them as to what they "need" vs. "want".