So, I used CFL's when I grew before, good results, but my setup was shitty. so then I decided to upgrade myself lol... and I bought a glow panel 45, works pretty well, after all the mixed reviews and opinions, ive come to realize the light is a pretty good light, but the results for flowering seem to be way better than veg. so my bright idea is to used a HPS light during veg, then switch to LED for flowering. opnions? and also, my biggest concern right now is... im looking at a 150W HPS system for about $75 give or take a few bucks. which is fine since my grow area is a 2x4, only growing 1-2 plants at a time... but I don't know much about the light systems, so Will I 100% have to get a cooling fan for a HPS light?
It'd be better to just use the HPS all the way through. Your grow space is small, but if you have it properly ventilated you'll be fine.
Your glow panel puts out 28 actual watts. the documentation for it says it will cover up to 5 square feet. I'm sure a 150W HPS will be much better at getting you to harvest with more lumen power.