C&C Should I Upgrade cages?

So, some of you might know that I adopted a piggy a week ago, which means I am now a proud owner of 2 piggys! I have been reading all about introducing the two and what not and have a question.

I have two boys... Cadbury is about 4 months old and Carlton who I just adopted is around 3 months old. I read that around this age they are in their adolescence stage so I'm wondering if I should make my cage bigger before introducing them to each to each other. I read that they can be fussy at this age which could cause dominence issues. Right now I have a 2X4 c&c cage. I should also mention that in my 2x4 cage is a 1x1 litter box so does that count towards the 2x4 limit or is that taking away from it? I was thinking of adding on a 2X1 kitchen area. What do you guys think? Will a 2x4 be fine or should I add on or do a complete different set-up? If I should add on, any suggestions as to how I should lay out the cage that would work best in my case? I'm open to any suggestions! I just want to make this easy on my pig's as much as possible. Thanks in advance!