I don't know about the hotel but Kamari & Perissa are on the 'beach' side (east) of Santorini. The beach is mainly a black volcanic grit, gets very hot on the feet, so suitable footwear is needed. Both have a varied selection of tavernas & bars.
The west side of Santorini is where you get the dramatic caldera views.
You don't say when you are going, but it will be very busy in July/August, Fira & Oia on the caldera are both busy during the day at almost any time of the season bcause of all the cruise ships that dock there, so be aware of that when you intend to visit either of them. The island is small so travel is easy, there is a bus service to Fira, then on to Oia or elswhere if required. To pick the quieter days to visit the caldera side you might want to check your dates on here nearer the time, it tells you which ships will be docking & how many people will be filling up the small lanes of Fira & Oia so you can pick a day to visit accordingly!
http://cruisett.com/ports.php?PortID=805&date=24
Sorry, no photos of the east side, but here's some from Fira & Oia,
http://www.flickr.com/photos/yiassas/sets/72157619631624019/
Santorini sunsets,
http://www.flickr.com/photos/yiassas/sets/72157619719672788/

Thanks for replying. We are going to be going in the last two weeks of June so hopefully it will not be as busy as July/August but still lots of sunshine!
Definitely going to be staying in Kamari and so we can easily travel to the other areas. We are mainly wanting nice Greek restaurants and some lively bars so hopefully we will get lucky, even though it is still early in the season.
Thanks agan for the info.