Here is a photo of the installation I did on our Islander.
You mention mounting the windlass forward of current fittings. Note that the windlass needs to be as far aft as possible, so it is over the deepest part of the anchor locker. This is essential to maximize the "fall" of the rode coming off the windlass.
Vertical windlasses are nicer looking, but horizontal windlasses do a better job in feeding rode into the locker. This is particularly important in installations with limited "fall".
It is also (strongly) recommended that you not ride to the windlass when at anchor, i.e. that the rode is secured to a cleat to take the load. You should consider this in planning your installation. The cleat to port of the windlass is the original centerline cleat.
I have also installed a SS anchor swivel since this photo was teken.
Brian