just to say, a 26 with a 32 is 21.9 g.i.
a 24 with a 32 is 20.3 g.i.

not a hell of a lot of difference. Depending on the weight you are carrying, and all the other factors we in webzland cant evaluate, you might wanna go lower.

only you can figure out what you need in relation to what the bike is presently.

heres a pointer, use a gearing calculator (sheldons browns one is good) and see what you have now as gear inch numbers in your lower gears. Load a crapload of stuff on your bike and hit a hill and see how it is, and how the jump of "x" gear inches feels like (to see if a 1.6 gear inch lower gear is even worth doing---ie, perhaps look into getting a diff rear cassette as suggested , up to 34 or whatever.)

have fun figuring it out for you and your situation.