just to throw in my .02 here i've been using 2x P300s by Platinum LED for almost 2 years now and absolutely love them! Platinum LED is one of the prebuild brands that you can really trust, which is naturally why they are on the pricier side. I also have a 300w galaxy hydro light that i use in addition to the P300s as a bloom booster. My clone/early veg tent runs 36w of full spectrum LED lights as well, the brand name on that light is ACKE LED, most people consider these "cheapo garbage LEDs" which they would be for anything other than what i use them for, with these "cheapo" lights i can keep my clones/early veg plants within 12"-18" of the lights with no negative effects.
In conclusion i recommend if you're changing to LED you simply do your research and go for quality, as the first responder had mentioned DIY COBs are a great option but quite pricey, not to mention a pretty big pain in the ass if you're not familiar with electrical circuits and soldering. Good trustworthy pre-build models will also be pricey but i personally recommend going with a pre-built model though simply because any quality brand (Platinum LED and Kind LED being the leaders) will have a warranty on it, where as no DIY kit will. I also recommend getting several smaller sized LEDs rather than one large one, gives you more control over the spread.