Bear in mind though, that you will have to strip down many features and styles to make a RT theme to look like these sites. We could guide with most changes but you will have to apply some on your own
In most themes you can find RokSprocket pre-installed (if you use the RocketLauncher) which is pretty awesome. You can also check on RokGallery but i believe you will find RS more useful. Either way, you will have to adjust some paddings and margins to make the images appear next to each other (without spaces between)