250W HPS or 400W HPS ???

Hi, no doubt you'll have seen my UFO/CFL grow @ https://www.rollitup.org/indoor-growing/281701-2x-90-watt-ufos-1x.html anyhow after I have finished this grow in around 3 weeks time I want to try out an HPS setup but due to the space I don't know wether to go 250w HPS or 400w HPS??? I'll post a pic in a min. of the cupboard, and post the measurements too....

I can tell you that I will be using a cool-tube, with an odor sock, perferated 4" or 5" ducting a 4" Systemair in-line fan and a small Can filter, the cupboard is fully lined with diamond mylar, I am using a DWC setup, with Co2, and have a Thermostat too, I also have 2 mini cfl strips for side lighting. - STELTHY

The cupboards dimensions are 50CM DEEP, 80CM WIDE, 175CM TALL, However after I account for the shelf at the bottom that contains my DWC pots, and nutrients behind the BLACKOUT PVC CURTAIN, and my fan, ducting and lighting area..... my "ACTUAL GROW-SPACE" is 50CM DEEP, 80CM WIDE and 110CM TALL - STELTHY

Ideally a 400w would be great because its all about big dense buds, but want to know if this is ok to do in the space that I have??? If to much light, or heat would be an issue??? Being new to HPS I am going to start from the bottom of the ladder and work my way up so as to speak, however I do have 2 full grows under my belt and Know what I am doing, its the HPS part I am new to! professional advice = GREAT REP! also I need to know about the height of the lamp, at the different stages of the grow, can I grow from seed with the HPS? I will be using a digital ballast capable of taking HPS and Metal Halide. will I still need to use a Blue spec ENVIROGROW light for Vegging? I welcome all info on my questions, pics diagrams links etc all welcome please HELP ME! ASAP cos I only have 3 weeks till I go shopping - STELTHY

i think you could manage a 400 in there with a cooling tube definatly

I am thinking a properly vented 400 watt hps could do you from start to finish. People will tell you that the nodes will be spaced out a little more from the HPS but considering your limited space, it wouldn't make that much of a difference. You have to factor in the hood for the light. This will cost you another 8-12" depending on the hood you choose. When the plants are young you are going to want to keep the light about 36" above the canopy. As they establish you can start to move the light closer. Once they are in flower you can determine the best height for the light above the canopy. I keep mine 6-8" above the canopy. Your biggest concern will be good circulation and temps, though you can go a little hotter as you plan to inject CO2.