i have a DR 150 myself,and am putting a 1000 in it as soon as i can,the 5x5 area is the perfect size footprint for a 1000w,not a 4x4 which is the footprint of a 600,you are much better to go with the 1000w,as thats what the tent was designed for,if you go with two 600's you are not getting the best spread of light due to your 5x5 area,plus cool tubes light spread isnt supposed to be that good anyway,if you had a DR 240,then yes 2 600s would be good,as for shades,if you want to go air cooled get a magnum xxxl ,its the perfect size and spread for your tent,or get a grostar if you dont want to go aircooled,as for your extraction fan,unless your tent is a new one your holes wont fit a 8" duct ,unless you cut your tent,so get a 6" L1 fan,hope this is some help,im a brand new grower so take what i say with a pinch of salt,