Garden doves have a better chance of surviving, it might be worth getting more than 2 just in case
The fantails are better in an aviary as they are not the best of fliers. You will need to drape a homing net (bit of garden netting) over the aviary till you think they are settled. 6 weeks is recommended but when I got mine they settle much more quickly
I am too far away in Worcestershire
Otherwise I currently have some spares