As long as you don't have the radio with the slanted RH side, you don't need a dash kit to install a pocket. The metal brackets used on the factory radio just get re-used on the aftermarket radio. You then buy a Nissan OEM single-DIN pocket (68475-35F00) or even a blank mask panel (68470-8B400 or 68470-60M00). I've used both. Both are also held by the re-used factory brackets. All you need then is the antenna adapter and wiring harnesses.
Here is my dash (04 SE w/Bose) with the pocket and single-DIN radio:
...and with modified blank panel:
