ASP.Net MVC3 Modify culture for date and decimal through or not Visual Studio?

I'm working on an MVC3 application with Razor. I'm having troubles using Dates and doubles on my views. Both my Windows and Visual Studio are English, but I want to customize the culture of my project in "it-IT". I found several articles how to manage different cultures, through the JQuery Validation Plugin or directly setting the culture on the page, but I'm a lot confused!!! The format I want use for dates is "DD/MM/YYYY", while for double is 1.234,32. So,

• How can I tell to Visual Studio how to use these formats (I checked on the Visual Studio's settings and there is only English)?
• MVC injects code to validate my fields, how to change it?
• What is the best approach?

Obviously any suggest would be appreciated. I post the code of my project:

Offerta.cs

[MetadataType(typeof(Offerta_Validation))]
public partial class Offerta
{
}

public class Offerta_Validation
{
    [HiddenInput(DisplayValue = false)]
    public int IDOfferta { get; set; }

    [StringLength(300, ErrorMessage = "Campo troppo lungo")]
    [Required(ErrorMessage = "Campo obbligatorio")]
    public string Titolo { get; set; }

    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:N2}")]
    [Required(ErrorMessage = "Campo obbligatorio")]
    [Price(MinPrice=0.01)]
    public decimal PrezzoIniziale { get; set; }

    [Required(ErrorMessage = "Campo obbligatorio")]
    [Integer]
    public int BuoniScontiMinimo { get; set; }


    public string Sconto { get; set; }

    [Date]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:d}")]
    public System.DateTime DataAttivazione { get; set; }

    [DataType(DataType.MultilineText)]
    [AllowHtml]
    public string Sintesi { get; set; }

    [DataType(DataType.MultilineText)]
    [Required(ErrorMessage = "Inserire le condizioni")]
    [AllowHtml]
    public string Condizioni { get; set; }

    [DataType(DataType.MultilineText)]
    [Required(Erro