Answering your initial question.

32/32 is identical to 34/34..

As Maelochs suggests, try the 34/32 before buying the new cassette. If you have enough adjustment with the chain,just make sure you have one extra double-link for the possible future cassette change.

Not all rear derailleurs will play nice with that large of a cassette, but you could look at your current derailleur setup to see if you could get an additional 1/4" to 1/2" space under it (adjusting the B-Screw).