minihawn...
If you intend to use the proper tire size on the front that are the same as a real Lambo, the tires will have a much larger patch contact to the pavement. While you are moving, it shouldn't be too hard to steer BUT when you are barely moving, such as when you are parking or doing any slow speed maneuvering, you may find it takes a lot of effort to turn those tires.
It is always nice to treat yourself to the best when you build. It is up to you to weigh the work and cost for the advantage power steering will give you.
Also I'd like to add, if you are using spacers to put the tires out to the fenders, that can cause the tires to travel through an arc as you turn. This could require more steering effort AND while you are driving, the tires "hanging out there" can really feedback to the steering wheel when they hit a bump. Power steering will dampen that effect.
RT