I went for the LG G Watch R and am very impressed with it (had it about 3 weeks now).
It was either the Moto 360 or the G Watch R and the G Watch R appealed to me more (better battery life being the main attraction).
But Android Wear is being (or has just been) updated to support wifi...
Some existing Wear devices have wifi capabilities and some don't - if a device does have wifi it's disabled in software as it's not (or was not) supported.
Have a read:
https://www.google.co.uk/search?q=android wear wifi&ie=UTF-8&oe=UTF-8&gws_rd=ssl
The Moto 360 has wifi capabilities that will be enabled by the Wear update, the G Watch R doesn't have wifi capabilities.
Initially it was thought that the G Watch R did have wifi but that is not the case.
The Sony SW3 does have wifi and it has built in GPS - it does not have a heart rate monitor though.
To be honest i don't think this is the right time to buy a Wear device, as there is likely to be a new wave of devices that all have wifi released pretty soon.
The current devices that don't have wifi will soon be bargain bin bargains.