hey cool

the question really is, what do you want to keep?

There is no need for heavy duty lighting unless you want to keep some SPS.

If I was going to do a 125 I would go the following route:

3 x 250 watt metal halides (I always go for the best I can find and afford, for me it would bee icecap ballasts and Reef Optix 3 reflectors, HQI.)

2 VHO actinics running the length of the tank (I have T-5s on my current tank because of the size and shape)

lighting and skimmer are what will cost you the most. Figure out what you want, that dictates what you need as far as equipment.