There are many fabrication shops where you can get bodykits and spoilers with custom designs.For the bodykits and spoiler,they usually take a week or atleast 4 to 5 days.
In your case,first select the type of spoiler you want and then have a visit to the fabrication shops on G.P.Road,if they give a high price quote,as they usually do for a spoiler alone,whereas if you have bodykits also done,then it will be very cheap than their primary price quote.If you want the OE spoiler with perfect finish,they will definitely charge you high.
So,decide on a design and then have a visit to the shops.