correct wheel size and backspacing for this size tire. help?

[redlinedeath]

3 of the stock wheels wont hold air, they go completely flat within 10 min. i have 2 brand new falken azenis 225/45 17s in my room, so i figured id just buy 2 more. with that tire size, what would be the optimum wheel size? (offset, and wheel width) i dont wanna screw the handling, and i need new wheels so i figure if i can afford them, i may as well go aftermarket and find something i like. thanks again!

just double checking, 114.5 is the correct?