How soon before the flight can you choose your seats? I am flying LGW to BGI in July and the seat maps are still unavailable. I am sure you used to be able to choose quite a while in advance.
Seat requests are a complicated issue at the moment, as VS are in the process of rolling out a new system which is running late, therefore the goalposts keep moving.
Once it's fully up and running you'll be able to request seats at time of booking but it looks like that won't be until the summer so for your flight you'll be able to request seats 60 days in advance - so sometime in May.