That's a fairly big job but beneficial. This spring I intend to undertake a similar project, since noticing my FPRC hose has a nasty crack (though not all the way through yet...)
For the V6, you'll need something in the area of 5-metres (about 16.5 feet) of hose. This amount covers all the standard hose and should leave a bit left over as "spare". I'm not certain how much one would need for the 4-cyl motor.
Go with silicone hose, not rubber. Silicone will put up much better with the underhood heat (not inconsiderable in these cars). Look for hose with a 3mm (0.118") bore and 2mm (0.079") wall thickness.
Do them one at a time. Pull one off, cut a new piece the same length from the new stock and replace it. Work methodically to avoid misconnecting anything and take care with the T- and Y-fittings; they can be brittle and snap easily. In the back of the manifold, things can be tight. Use care and, if necessary, remove the bracket holding the VRIS and purge solenoids in place to get at all the hoses there.
Just be thankful you don't have to replace the vacuum hoses on the 3rd-gen RX7 <*shudder*>
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