Yes get daylight tubes and yes a 4 foot tube is 36 watts. that's ok.

You could go with a conversion bulb but flouro's will due for veg cycle.
A 600 watt HPS is all you need for flower.

This is how I setup my lights. I used to and will do flouro's for beginning veg.
I have a 1000 HPS with ballast and a 400 MH conversion to finish veg. They love it. The secret to high watt lights are get the biggest ballast you can handle. A smaller bulb than the ballast will work. That's how I use the 400 MH in a 1000 watt ballast. It has to be a HPS or MH type ballast and conversion bulb to work accordingly. They have New ballast will work for both with out problems or conversion bulbs. Big bucks though.

So get a 600 or 1000 ballast HPS or digital ballast for both. A 600 watt HPS hortilux or sunmaster bulb. If you want to veg later you can get a MH bulb just make sure it's conversion if you get a HPS ballast.

My bro's 400 HPS blew on him and days to order one. I got him a regular 250 HPS at slowes till new bulbs come in. Now he runs the 250 untill they get big enough for the 400. He thinks he is saving money and maybe. It works.

Are ya confused enough now ? Go get the flouro's you can think about the others you have time.