upgradable lights?

[eric b 125]

i am not so new to saltwater, but have yet to delve into reefs. i am working on a 125 that will become a reef soon. is there any kind of lighting fixtures that leave room for an upgrade? my tank is 6' long and eventually i'd like to move to an 8' long tank. i'd like to buy equipment that i'll be able to use on the larger tank. i'm sure by the time i get around to buying a new tank i'll probably just start over fresh, but in case i want to transfer equipment, i'd like to know what my options are. thank you in advance.

 

[wangotango]

The easiest would be metal halide pendents. You'd need three for the 6' tank, but it's easy to just add another for an 8' tank.
-Justin