Zhuge Liang

Personally, I’d go for Chaldea Boys collection. I got my second copy of him from it last year and I believe he has a Rate Up in this year’s

Boys Collection would be a better choice. If I'm remembering right, Proto Arthur is on rate up the whole time but the other Servants will rotate. This way, there's only two of them on rate up on that one day.

If you go class summoning, Waver will share the spotlight with Tamamo and Sanzang.

In short, CBC has 1 in 2 chance while Class Summons has a 1 in 3 chance.

Going by probability of getting him alone Chaldea boys is better, but remember that he shares rate up with Arthur who is complete trash, only pull here if you don't mind that outcome.
In the class based campaign he shares rate up with Tamamo and Sanzang, so the chances of getting him are lower but those 2 are very good servants unlike say Arthur...
If you can wait Waver will have 2 solo rate ups next year.
Sanzang goes West rerun in April and Fate Zero Rerun in September

There is no significant difference in your chance of getting Waver from either banner. Chance in CBC will be .4% due to shared rateup with Arthur, with a .2% chance of spook. Chance of getting Waver in class summoning banner will be .33% of getting Waver, Tamamo or Xuanzang, with no chance of spook.

I spent one summoning ticket on Shinjuku part 2 2 hours ago and summoned him then :D 0.062% chance
I think odds will be better during CBC but he'll be on rate up with Arthur so consider who you'd rather get if the wrong rate up 5 star is summoned.