You'll need to order a set of lower motor mount pads, that bolt to the crossmemeber. It will require drilling the proper holes in the right place. You can get help and parts from TA performance, the biggest Buick source. Headers, mounts and performance parts are available there. It's a good engine and light weight. It should not present too many issues beyond the special lower mounts.
Trans will swap directly. I believe the starter is on the same side as well as the fuel pump but my memory is cloudy on that.
Click this and scoll just short of half way..