How many plants?

So just picked my self up a tent 120x120x200cm. First grow was wondering how many plants id be able to fit in this tent? Id be running a 400w sodium light with a reflector. Also strain wise im gunna mix it up hopefully get 2 or 3 strains growing at once assuming they have the similar flowering times and height. Is it possible to grow both sativa and indica in the same tent? If so what would be the main problems i might come across with them being in the same tent?

Being male and female.. You could do it. I wouldn't do more then 5 plants under a 4... Depending on pot size, try to aim for one gallon for every foot you are planning the plants to finish at. So if were talking 2-4 gallon pots I'd say 3 MAYBE 4 plants


Edit: on second thought.. (I hate HPS) if I were you. I'd plant a few, get a really nice female, and put the 400 on one monster plant... Maybe scrog if you have confidence. But that's just me