Rollitup

2 T3-2100 lamps would be a good combo in a 4x4. $530 each so 2 of them will run $1060 and provide 450 watts of output. Or a couple T3-1750s, 2 would provide 375 watts of output, $1000 for both.

T3-1750s are available. T3-2100s in a couple weeks. There are other options that would work in a 4x4 tent. On the main page at tastyled.com there is a chart with recommendations based on various spaces, PPFD, wattage, and cost. If you see something that is not listed in stock a request can be made.