They have specific part numbers for each, if you try to replace the hoses with straight tube you're most likely going to end up with pinch points that restrict flow. The heater hoses, well really all hoses, on our trucks are molded and formed from the factory to conform to very specific routes and curves.
Check out oemtoyotapartsgroup.com for a schematic of our trucks and you can pull part numbers for each there, then take those numbers to a dealer or cross reference online for aftermarket. Your last option is to find good ones on a junkyard rig, but that's hit or miss.