the i6 and v8 have different steering components, including spindles, tie-rods, centerlink, idler and pitman arm. The coil springs for the v8 are beefier to hold up that motor, and the 4-lug axle and brake system is different. And the Rear end is different.
You CAN keep the tie-rods, centerlink, idler and pitman IF you go with the CSRP Swap kit #2 from discbrakeswap.com. that will upgrade you to beefier spindles, with 5 lug Disc brakes. You will still need to replace the front springs and the rear-axle, though.
The Upper and Lower control arms for the 6 cylinder and V8 are the same, so you can leave those alone...though if they are older, they might require some inspection and freshening anyway. I recommend a new LCA, Upper Ball Joint, and Moog UCA Shaft Kit.
you're probably looking in the 1k - 1500 range BEFORE you build and install the motor, depending on how well you source your parts