Wimbledon away tickets will be as hard to get as hens teeth.
1 per season ticket holder on a first come first served basis is my guess.
I went to Wimbledon last season and the away end is no bigger than my back garden!
Even the supporters clubs will be limited to the point that you have to be a season ticket holder and will be allocated to members that have been to virtually every away game - I’ve only missed 2 games all season and have 2 season tickets and I’m not guaranteed to get a ticket!
I would not recommend Gillingham away end. One of the worst away ends in efl. That should be your last option. But you should be able to get tickets easily for that.