Thanks a million for all your help!
Please direct me to the best choice of
t8 32 watt 4100K lights at businesslights.com
There is a large selection; I figured you would know the best.
If you only need 4, then the only 4-pack that I would buy is
the USHIO 32W 4100K 86 CRI T8 Fluorescent Lamp 4/pack, an extremely long lived lamp with excellent maintained lumens, extremely well designed, has the longest life with a rapid start ballast; I run them with an instant start ballast - the drawback of the instant start ballast is that the lifespan of the lamp is slightly less. A case of 25 costs 47.50$. Entirely a superb lamp, made in Germany. DO NOT GET the 78CRI lamp - it is a half dollars cheaper per lamp, but the phosphorus quality is not as good, and the lumens are less. This is a good enough lamp for indoor lighting, but I would not grow with it, based on my visual inspection of the spectral distribution plots on the USHIO website.
If you can justify a case of 25, the TCP lamp made in China, which costs 62.50$ per case, puts out about 10% more lumens, and is designed to operate on instant start ballast.
I am not sure about the design details, about how a lamp is coaxed to produce more lumens for the same wattage, but my hunch is that practically speaking, overdriving either lamp would be completely satisfactory. If you are spacing your lamps so that you have one lamp per square foot, the USHIO 3050 lumens per square foot is lots for most applications. It mainly depends on how many lamps you can justify buying at one time, but I am running both the 86CRI Ushio, and the High Lumen TCP - if I was on a budget I'd have only purchased the Ushio's, and OVERDRIVEN them. This lamp, when OVERDRIVEN, puts out about 5000 lumens, which I have verified with my digital light meter. So it depends partly on the number of lamps you wish to run, and if you'd like to spend more on the XHL TCP, but the 86CRI USHIO is very nice and should work quite well. If you're lucky enough to have a 40 watt fixture to run them in, this would automatically overdrive the lamp to 40 watts, and in that case if you were to use the USHIO, run at 40 watts, they would probably put out 3800 lumens, a very agreeable amount. An XHL lamp would probably be pushed to 4100lumens, lots either way.