Best combination for Charisma buffs

[Exarduffman]

What are the best drinks/food/chems for maximising Charisma?

So far, I've found the following combination to give me a total buff of +9 charisma:

Most beers (inc Dirty Wastelander) (+1)
Grape Mentats (+5)
Day Tripper (+3)

However, I have not found a stable supply of Day Tripper.

Are there any other chems etc that I can stack with these three and also, is there a dealer who regularly sells Day Tripper?

I have also gear which so far will give me +7. I believe this can be higher, but have yet to find a sharp helmet and right arm. Also wondering if there are any cloths that will allow you to wear a full set of armour while also giving +2 charisma, the Summer shorts give +2, but won't allow the use of a chest peice with it.