Hi Dingo, Holy Wars & All
10x50mm binoculars are a fantastic choice for hand-held, all-round astronomy use. I've had a pair for 35 years and they're still my most used binocular, though the 15x70s are catching up now I've got a proper mount for them.
10x50s are light enough to hand-hold yet the magnification gives a field you can hold
reasonably still and the 10x magnification makes for a slightly darker field than the 7x50s, but still giving a good-sized field. A nice balance.
If you go much bigger than 10x50s you'll need a tripod or mount to put them on to hold them steady.
If you are using the 8x40s for the moment, attached is a .pdf of a map showing the area between Crux and the Eta Carinae area -- one of the best areas (if not the best) to scan with binoculars.
See if you can id NGC 4755 (Jewel Box), IC 2602 (Theta Carinae cluster), NGC 3532, NGC 3766 and NGC 3114 (unlabelled on the chart, mid-right at about 10hrs and -60 dec) for starters. And then of course is The Eta Carinae complex.
How powerful do you need to see the Herschel's Jewel Box (NGC 4755)? Well 1x6mm will do -- it can be seen as a small haze surrounding Kappa Crucis naked-eye from a reasonably dark site.
If people do develop an interest in doing binocular astronomy, there is a column devoted to it on the all-sky map page of Australian Sky & Telescope ...
Best,
Les D