Quote Originally Posted by Rusty Trichome
Shop light fixtures are great for young clones and seedlings, but keeping them within effective range of a mature plant can get tricky. A four foot plant, flowered with your shop lamp, will yield about the top 6" of plant, if the light is above the plants. All else will be too far away, and thusly have insufficient lighting. The problem I had with the side-light CFL lights, was that heat rises, and since you have to 'snug' them in to be effective, it can bake anything above it. (other branches, fan leaves)

Those spotlamps seem to give more heat than lumens, too. Not good for a closet grow. A 250w HPS would work much better, with some ventilation and air circulation inherently required. A 400w would be optimal, but it would come with a serious heat problem you'd have to look into solving, prior to purchase. Plus, you can veg with HPS if need be, or use one of those switchable ballast systems.

Your disappointments grow in direct proportion to your expectations...
...Yields are irrelevant. Results are relevant. (you'll find out yield, when you reach your first harvest at full maturity) :jointsmile:
Rusty makes a good point.
Firstly, let me answer your question: Yes, yield is affected by the size of the plant (of course a taller plant is going to have more bud.)

Being as how this is your first grow (obviously), your first concern is to get a female plant... Secondly, to get that plant into flower properly.

A 1000 watt light is nice, but you're going to have some serious heat issues to deal with now, as that thing is going to give off a LOT of heat.
When I said "you could put 1000 watts in there" I wasn't saying it would be optimal... I hope you're prepared to throw money at some GOOD ventilation fans to help deal with that.

Keep your expectations low, and you will be less disappointed when it doesn't turn out so good this first time. Don't expect a lot, and then if you get a lot, you can be pleasantly surprised.