My DS was hopelessly caffeine sensitive. I would have one "normal" tea in the morning, and then decaf tea (which tastes the same) and decaf coffee.
Tetley make a reasonable decaf tea and decaf green tea. Personally I hate instant coffee, so I used decaf coffee beans; the decaf coffee bags are OK too.
It's all a bit trial and error - what you really really have to watch out for is the horrible cycle that goes:
bub doesn't sleep/need coffee to be awake enough not to drop bub/bub gets caffeinated/bub really really doesn't sleep/need more coffee/etc.....
That's what i am worried about. Might try to cut down to one normal strength a day and then if i really want another i can get some decaf bags.

O and lawnmower grass doesn't sound very appealing to me what so ever

Also another quick question - if i had a normal strenght tea in the morning how long would it take to go through my breast milk? Just something for me to look out for.