Well a normal tranny swap is between 5000-6000. I'm not sure if it's even possible you would have to compare the two transmissions. If it can be done I would think it would cost at least 9,000, probably more.
More than it is worth. First you need to find out if out of some miracle it bolts right up... The IS is an inline RWD which makes me guess that the configuration for your 4 banger is just not going to work well.