Excellent. With those specs pretty much everything is fair game.
Since you are using 2 lights to cover 60 inches of length it is going to be important you choose your reflectors wisely. 24 inches of depth is easily reached by 250W 10 MH granted you are using one of the common hobby-type bulbs like XM's, Ushio, Coralvue ect ect..
So to cover your entire tank you are going to want a reflector with the most spread or an oval, maybe rectangular distribution.
Parabolic type and MH Pendants such as PFO and Coralvue have rectangular shaped distributions where as Pacific Garden Supply's Luminar3 reflectors have a square distribution while also covering more area. You will need to decide what you have room for and $$ for.
The higher the bulb/reflector the larger the distribution but the lower the PAR (light intencity). So if you plan to keep mostly SPS (High light demand) you would want to have your bulb lower than if you were to keep soft corals (lower light demand).
It sounds like you are just getting started out so I would reccomend my happy medium of 8 inches, but play with it. I try to never make anything permanent (don't look at my tanks plumbing
)so I can easily test variants out.
To do things right go to Sanjay's site:
http://www.reeflightinginfo.arvixe.com/
Take a look at the 250W MH bulb comparrisons. Choose your bulb. Then go to advancedaquarist.com an look-up Sanjay's articles on reflector testing. You will end up with a complete picture including spectrum, intencity, and distribution..
And now that I am done you can also read our ~Let's talk about lighting~ Thread
