It doesn't matter what the dpi is, only how many pixels you actually have.
If you want a 10 inch wide photo at 300 dpi, you need 3000 pixels wide. That's 3000 pixels at 72 dpi or 3000 pixels at 300 dpi. It's just a matter of what your display can do. Monitors are typically 72, print 300.
In photoshop you can always change the dpi of your sticher output to your desired output resolution. Just make sure you do not "Resample Image" in the Image Size dialog and you'll be fine.