One double pole relay or two single pole relays for live and neutral?
I see the next advantages/disadvantages:
1 double pole relay:

+ smaller area
+ synchronous switching of live&amp;neutral (if any appliance needs this ...)
+ easier to control
- price
- more challenging PCB routing for high power
- if the relay fails, then ... you have no control

2 single pole relays:

+ cheaper
+ easier to route on PCB (especially on higher power)
+ if 1 relay fails, you can still switch off the other one
- increased area on PCB
- there might be timing diffs between switching live&amp;neutral (if any appliance is affected by this ...)
- you need to control 2 relays, not 1

Depending on this (let me know if you see other pros/cons or if you see it differently) you can choose your best option.
(Personally I need a latching relay for ~10A @ 230AC , and I think I will go on 2 SPST relays because of the disadvantages of the 1st option)