Do 1 plant as that plant flowers you veg your others the plants you flower will be progressively larger and yield more every time ,you will end up with monsters harvested every (insert flower time of strain here)8 or so weeks.
One plant can yield well the plant below is filling a 2 metre by 2 metre tent easily, so with a 4x4 foot tent it won't be long into that flower and harvest schedule where you will be filling your tent very very easily in fact with this system you will end up buying a larger tent and then another and another cause you won't want to miss out on breaking your yield record every time you flower cause each plant has vegged longer and longer .
example if you start with 3 plants, let's call them tom dick and harry .
Tom and his gang hang around vegging for 4 weeks then tom is flowered which let's say takes 8 weeks .
While tom is flowering for 8 Weeks dick and harry are still vegging.
So tom finishes then dick goes in by now dick has had 12 weeks of veg = monster when dick finishes flowering harry has had a whopping 20 week veg and you can't fit him on your House anymore, of course you can change it up however you want ,what I'm getting at is a 1 plant flowering at a time stacked veg time perpetual which I feel would be the easiest and foolproof way to start perpetual whilst not sacrificing any yield in the process (