I think sitting down is better especially if the room is tiny. I haven't been too or done a meeting where anyone stands.
I'll continue to remain seated. It seems to work.
It depends on the situation and the room, but generally standing commands presence and attention.
Also forget notes, just rehearse it enough times so you are confident with speaking through the technical bits. Nothing worse than getting tongue tied, so practice the best way of saying it, then work on timing and delivery.
My last presentation, on a iron smelting plant, contained loads of images from Terminator 2. Nobody laughed. EXCEPT ME.