So, I need a weaker driver.. Right? Like ideally you'd want a driver that can just run the 4..
That driver can use all kind of ac power. If memory serves me right, the MWs are pretty much as efficient at 80% as at 100%. But if you're never going to add a 5th cob you'd save a pretty penny on going for the 185. Tme.eu has the 185 @€47.40 while the 240 is €61.90...
I was actually considering a 5th cob. Now or in the future, so might as well get a driver that supports it, if it doesn't affect the efficiency.
I heard 1400mA was more efficient than 1750mA, is that wrong? I'd rather run it a bit weaker and save power, than run it full blast.
For my own probably uneducated reasons I went with 1400mA, but I can't advise any way or another. But as for the cost of power, logic dictates that given that if the other factors are good, more power equals more bud. To some ill-defined point people argue over. So maybe you should do the math on power consumption vs what yield you seek? How much are you willing to spend to produce how much? Only slutty girls smoke for free eh lol? I once did the math on electric generators whit insane fuel prices, and it would still be cheaper than buying weed even with 0.3 w/g.