Having a Duratec myself i'm not exactly positive on where it is located on the Vulcan. Hopefully someone with a Vulcan can chime in and let you know or post a picture for you. As far as what it looks like, if you've never seen one before here are some pictures of what a standard starter looks like.
I have an Essex and mine is: look under front of car, past radiatior and theres a piece of steel running from one end of car to the other it will b obove the piece of steel preety much under the block. Have fun replacing it, I know I did.
I've never replaced it on a Duratec or a Vulcan before but on all the other cars i've worked on it was as easy as two bolts and one electrical connection. The main problem i've had when replacing a starter is any clearance issue when trying to remove or install the new one. And as i mentioned before since i haven't done it on these engines i'm not sure if that will be an issue for you or not. As long as you get a good quality one it should last quite a while.
Usually i've never had to change the starter more then once per vehicle (if even that) and i had a few vehicles that lived to 130-160K before. Only once did i have to replace a starter on a car twice and that was because i tried to go with the "discount" one the first time and it crapped out after a few months.
Most part stores will have ones that have a lifetime guarantee, i'd suggest that one from past experience.