I would definately get the tank drilled. I would also get 250 w metal halides, but Scooterman and I disagree on manufacturers. I prefer the Icecap E-ballasts due to performance numbers from this test done here....
http://www.reefsanctuary.com/forums/showthread.php?s=&postid=1674#post1674
long thread I know, but definately helpful. I seriously reccomend reading ALL of it.
I'm not as thrilled by Champion because of a couple of things I've read here....
http://reefcentral.com/forums/showthread.php?s=&threadid=234437 (not meaning to start a flame war or step on any toes...just passing on info)
If you decide not to go w/ the E-ballasts, (they are more expensive on the initial set up, but the benefits outweigh the expense in my opinion.), here is a link to an explanation about the different kinds of ballasts...
http://reefcentral.com/forums/showthread.php?s=&threadid=201570
Read in conjuction w/ the first link to the bulb testing, you should be able to decide what configuration suits your needs.
One thing I've been looking more and more into is whether or not to run w/ a DSB in the tank. I've decided to run w/o on my upcoming 58 gallon. There are several people here who dont run DSB's. They either go bare bottom (Tank Girl) or run w/ a very shallow bed of either crushed coral or sand (Mojoreef).
Here is a link to (yet) another long discussion, this one concerning DSB's...
http://www.reefaquariumguide.com/forums/showthread.php?s=&threadid=28982
This is the thread that caused me to decide that I should at the very least run any DSB remote, (meaning in a seperate sump/container that is able to be taken off line should it require maintenance).
Since reading that thread I have stumbled into another option recently that is the use of Starboard, (cutting board essentially..) as a bottom for the tank....here is a link to another ridiculously long thread, you might find it interesting also....
http://reefcentral.com/forums/showthread.php?s=&threadid=223301
BTW, I dont neccessarily reccomend reading all these threads that I've linked you to in one sitting, your body will go numb and the wife will think you've been kidnapped.
Finally as far as plumbing goes, you need to figure out what you want to keep, (you should have this figured out by the time you decide on your lighting preference...) as it will dictate you plumbing needs as well. I'm planning on keeping SPS and clams, w/ at least one anemone, so flow will be an important thing for my tank. Here is a link to a thread about plumbing...
http://www.reefaquariumguide.com/forums/showthread.php?s=&threadid=33260
No more links for now, sorry to have hit you w/ so many...:explode:
Hope all this helps,
Nick