Best to use a battery hand drill. Drilling needs to be slow and gentle so avoid hammer action or corded drills.
Reason to avoid corded is because at 240v (domestic) and 110v commercial there is water sloshing about at the drill site. With a low volt hand drill its much easier, safer and more practical.
RE: Drill selection - that is a very personal matter. Me? I attend a lot of demos and for five years used a BOSHH 14.4v drill without problems. But then some **** Nicked it from my stand at Tile & Stone. Thats it in action below:
I could have bought a replacement BOSHH but instead chose Dewalt based on of all stupid things - the colour.
My thinking was it looked brighter in photographs with used with our yellow drill plates. The BOSHH looked dull
Biiiiiggggggg mistake.
My BOSHH was a much better drill that this DEWALT.
At the time of the theft I needed a drill in a hurry so paid a premium of £170 for it via a local shop. But if I had time to research I think Screwfix were doing it for about £117.
In hindsight (and in future) I will go back to a BOSHH 14.4v with spare battery.