I have no experience with any of these, but this is my 2 cents, as I was also on the fence about which one to get, if I were to choose between the 2 Logitech wheels.
Both the G29 and G923 are good options to start out your racing with. From doing some online research, apparently, the G923's pedals are better compared to those of the G29 but other than that, they should be very similar. The Force Feedback on the G923 is also improved over its predecessor.
You can also look at the Thrustmaster T300 RS GT as an alternative option, but it's generally around the R9k mark.
As an opinion and just my two cents, if I was looking for a wheel set at the moment, I'd start with a fairly inexpensive set. Maybe a good condition, used G29 (I've seen some going for R2500 - R4000) and then if you eventually get the hang of it and maybe feel like you'd like even more realism and immersion, then only start looking at direct-drive systems, something like the Gran Turismo DD Pro.
I would personally LOVE to get a full MOZA Racing set but believe they are PC only.