It is hard to beat flood cooling for drilling large holes with HSS and insert drills. It is also almost imperative when working 304 or 316 stainless, because the heat concentrates in the cutting zone, and this burns the tools.
But in aluminum, I have had really good luck with a Trico unit. It provides enough air to move the chips (not a wild blast) and enough lube to keep your tools from loading up.
For cutting steel with carbide, the Trico unit is also good. The extra heat may cause a bit of smoke, but that would be objectionable mostly during heavy cutting. You would want to ventilate the smoke. Using the Trico with HSS on steel is a bit more restrictive, because it does not provide high density cooling. However as you indicated light cutting and such, it should be fine.
I highly recommend the Trico unit. Even having flood cooling available on my Haas, I still use the Trico when I don't want a big mess of wet chips, and I prefer to not soak my 4th axis rotary nor my speeder as well, so I use the Trico unit under those circumstances.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)