hi mate, the heal tool is good for that kinda thing. You can choose the heal tool, set it to 'replace' to paste in chunks, and then switch it to 'normal' when you need to heal the blend line....

so basically, if you have 4 photos you need to blend, open them all together.... make a new doc with a canvas size big enough to hold the finished composition. then when you use the heal tool, you're essentially painting one picture or texture into another. So you define the sample you want to import (on mac you alt-click on the picture you are lifting) and then you just paint it into the combined document. Once you have your chunks of images in there, you can use the 'normal' setting to select areas that need healing/blending and fix them up. if you need any more help or this doesnt make sense message me. Im not great at coding but im pretty useful in photoshop and illustrator.