You look like your ready to grow some serious plants! :jointsmile:

Though, I don't think you're going to be able to meet some of your expectations with that sized cabinet. Flowering plants can easily shoot up to over 2', even the squattest varieties of indica. And that's not including the extra height from the container that it's in. You could just take away from vegetation time and would end up with shorter plants in the end, but the yield will be diminished severely.

The cabinet setup you've depicted looks very efficient, and I'm not trying to say that you can't produce some good buds in it...because you certainly can! But, if you can get your hands on a larger & similar cabinet for just a little bit more money, it would be money well spent. Also, you said that you won't be using the utility sections of the cabinet, but you're still going to be using a similar ventilation to the one shown in the diagram, right?

With adequate ventilation, similar to what was shown, you will be able to run the 1000W switchable system you're planning to buy in the cabinet. It really looks to be a decent system, so go with it if you can afford it. (I like the idea idea of a fully-suspended ballast.) But even with good ventilation, it still might get pretty warm in there...especially in vegetation, when you're using the MH bulbs. Even digital systems can make things warm in tight locations...so, just don't skimp on the ventilation if you do plan on going with this fixture, and you'll do just fine with it. I still think you'd be putting a light like that to better use in a larger enclosure, though.

Check out Project 420 for a myriad of reputable seedbanks. I'm partial to experimenting on new seedbanks based on several factors; new strains/crosses, competitive prices, solid reputation, etc. I've tried at least a dozen different seedbanks, and I've yet to find anything truly bad to say about any of them. Some just take a little longer to reach you, compared to others, but they've almost all been primo quality seeds...from germination to harvest.

Keep reading through the archives of this forum...you'll find more than enough insightful content to keep you busy for a long time!