I was reading your grow journal and was impressed up to the point where things went a bit off. You mentioned you were getting near 90 degree temperatures, it might actually work with a 50w if you added C02 with a simple DIY yeast version.

At 90 degrees you can increase the amount of CO2 the plant will want to use and you get that special zone of increased growth and safety because the plants will be expiring at 8x the normal evaporation rate thus staying cool.

In larger grow rooms this requires a decent amount of equipment to pull off but in these small PC case grows it makes sense that something like a small yeast bottle and release should increase the CO2 in the confined space quickly and effectively making it worth it. I mention yeast because it cheap but a CO2 bottle or anything else would also work.