I had a look at the fixture you mentioned and I suspect (just guessing based on how much light I know a high output fixture can churn out it without having actual PAR readings) will be too much light. Running two of the bulbs will work, but you may find you'll have to mute the output. Raising the fixture is the best option (offers better spread, reduces/increases intensity based on height raised), but window screen is another option. A shorter photoperiod will also be good practice; the timer will be of good use. You can start small, say 5 hours, and increase/experiment from there. The Odyssea fixture will be a good investment should you ever need more light, but you can also reduce its default output to suit your needs.
This is great to hear. I think i'm going to buy them!