Thanks guys, this is the model I have at the moment: https://www.mitre10.co.nz/shop/fuller-pro-ratchet-handle-socket-1/2-inch-drive-silver/p/254218 But it sounds like I might need a "Ratchet 1/4 inch drive" instead of a 1/2 model? And then to find a 1/4 compatible Philips head bit (perhaps a normal philips bit from a driver bit set would fit that?). Or https://www.bunnings.co.nz/trojan-11-piece-ratchet-screwdriver-set_p0131348 which seems to come with the ratchet and head although not a particularly long one.
The amount of downwards force needed would likely still be an issue but maybe with just the right amount of wood pieces I can get something stuck between it and the ceiling.