tire question

From Hawaii, 1 post

my car's oem tire is 195/65R15. i'd like to make the car look a little sportier. would it be okay if i put 205/55ZR15 tires? how would it affect the handling, mileage or other? could i go even bigger? on the same note, could i/should i go to a bigger rim size? this seems to be all the rage nowadays. by the way, i drive a 1990 nissan maxima GXE. thanks, everyone.