The Cree LED lightbulbs (that's all I recommend, don't think this applies to other stuff you find at the store) veg fine. Use warm:cool at a 1:3 to 1:4 ratio. I'm vegging this plant right now. I flowered this harvest using them (at only 21 watts per sq. ft.).
Now, about LED generally, and what you heard. The LED market is extremely predatory. A lot of stuff is sold under-speced. I would encourage you to come to the LED forum if you want to do more than a few lightbulbs for sidelighting. Price doesn't mean anything because there are some very expensive lights on the market which are little more than rebranded versions of the inexpensive stuff you see on Amazon and eBay. The important topic is efficiency.
Basically: if you're not willing to pay for efficient LED (backed by datasheets, which is a limited number of brands) or DIY for half the price, it's more economical to buy CMH (for tall spaces) or T5HO for short spaces (or, do the Cree LEDs if you have some DIY skills to rig up the mounting, etc.).
The LEDs you find on eBay and Amazon require 50-60w/sq ft for tall'ish grows. (The other day one guy said he was going run his at 72w/sq ft, or something like that.). At those levels of heat and energy, CMH and T5HO are more cost-effective for a similar purchase price. (Or, if you run those LEDs at lower intensity, they produce airy buds. Especially for taller grows.).
The link I gave you in the previous post has all the info you'll need if you want to use lightbulbs to various degrees. I strongly recommend transferring some watts (of light) from the top to the sides (sidelighting) as much as you can. I think that's a huge win.
