Good choice, the dry lube should work well, flood coolant is totally impractical, unnecessary and messy for your situation of drilling holes in thin metal boxes.
They sell it in cans too that you could dip a brush into and clean the chips off the bit.
Are you talking about a cnc machine? I thought we've already been through this.
If that's what you're asking then the Deepgroove taig would be your best bang for the buck but you wouldn't use it for drilling but for milling out the holes with a small endmill as has been mentioned before.
Cnc milling machine
Hoss