In a word - yup.
There's literally hundreds of pictures of GTX690s inside the likes of Bitfenix Prodigys etc circulating the internet.
The issue with the Titan Z is that it's tripple slot, so very few ITX cases will support it, the NCase M1 being the main exception that springs to mind.
The R9 295x2 however is more straightforward as it's a basic dual slot cooler with an additional requirement for a 120mm fan mount, though you would need space to route pipes so it might not work in all cases. There should be a decent amount that it is compatible with though.
Awesome thanks, I am actually going to get the Corsair 380T with the Asus 295x2. Making a LAN PC when I travel. Thanks!