Rudolf,

I'd like to suggest 2 600 watt lights, even if you don't need the additional light right now, your going to use it eventually - You can also get adjustable digital balasts, but honestly, if you can keep the temps under control, there is no such thing as "too much light". Heat on the other hand... Well that is another story - I would think that a 14k btu portable or even a 12k portable would keep those temps under control, I've seen them brand new with a dehumidifier built in for less than $300, I've seen them used for $75

A portable in room unit can also cut down on your filtering issues, but I'd still always recomend a carbon filter, even if you do a DIY filter, they're cheap, and very good at their jobs. I've got a 2200sq ft apt I'm in with less than a 2x3 footprint, without my carbon filter, I can smell it outside of my house - This isn't an issue where I'm at, but I don't like the smell ALL THE TIME, I built a $10 carbon filter (actually $7) and viola, no more smell!

Venting, exaust, intake, cooling, all very easy stuff to do, and I'm more than willing to help, as are other people here.

As far as lighting, don't go smaller, always go bigger. You can dial a light down, but you can't turn one up, so if you get 400's now, when you expand to a 10x10, they're practically useless, they'd just be veg lights, which would be a TOTAL waste of power (IMO)

Just my 2 cents