you can't switch out 250 watt halides for 150s without rewiring. the lamps are different lengths.
150 watt halides will not be enough for a 30" deep tank.
i would use a 8 individually reflected T5 HO
lamps per 3 feet, or at least 3 x 250 watt halides with quality reflectors and quality bulbs and ballasts. there is a difference. you definitely get what you pay for.
as for LEDs, there are many to choose from and some are good, some are not. if you aren't going to DIY it, they are going to cost you well over a thousand dollars to light your tank. possibly 2 thousand.
the ones you see selling for a hundred bucks aren't fit for your refugium.