If you buy the shifter brand new from Summit Racing, Jegs, etc then it will come with a detailed instruction booklet. The instructions are very easy to follow and it will also show pictures of what bracket (supplied with the kit) that you will need to use for the transmission cable.
I have installed several B&M and Hurst shifters in the past. The job itself is not all that difficult. You will have to rewire your reverse lights and neutral safety switch. Again, the kit will include the switches that mount on the new shifter.
Due to the fact that your car is a column shift, you will need to change the steering column to one that does not have the shifter mounted on it or it will look very awkward having 2 seperate shifters!!!
If your car is all original, then you may want to reconsider doing this. As FISHMANJOE stated you will have to drill holes in your floor, you will have to cut the original factory wiring and splice in new wires for the backup lights/nuetral safety switch, and you will have to change the steering column.
If it is not all original and some modifications have already been made, then this would be a real good looking addition to your car. It really all boils down to you and your own personal likes/dislikes.
I hope this helps and if you decide to install a custom shifter, it is not that difficult to do. Just read the instructions carefully and take your time during the installation.
Mike