Will my order from Dell really take that long to get to me?

Well basically, I ordered my Alienware Aurora R4 through the Dell Website Yesterday (Sunday, 02 September 2012) and they told me that they will send me an email to my hotmail when I'll be able to check the status of my order. I bought an Alienware Aurora R4, and I did make quite a few changes (like I changed the hard drive to 256SSD+ 1tb SATA, I changed the memory to 16gb, I got 3Gb amd RADEON Graphics), which were quite expensive, and all in all the computer was about £ 2535, including a 16gb lexar usb, a headset and speakers, so there were quite a few Accessories too. So, when I woke up today, I checked the status of my order and it said that the EDD (Estimated Delivery Date) is 24/09/12 which is about 20 days away, and well to me thats's quite a long wait considering I payed so much for my Desktop and anyway Patience isn't one of my virtues So I just wanted to ask everyone out there that will my order really take that long? Or do dell Over-Estimate their orders.And will my order being changed up so much, and me having extra Accessories, slow down the delivery? And if you want to know where I live, then well I live in Portsmouth, Which is south in UK, apparently I've heard that Dell delivery in the UK has for the most part been quite quick, but I'm not sure if there's a Dell store nearby me. And just to let you know that even though I ordered it yesterday, my order is still 'processing' till now and I haven't received any email from Dell updating me on my order, I've only received one email right after my order Acknowledging my Order but except from that I've had no updates. Is this normal for dell or do Dell normally not take this long to process orders?
Also, if you could answer in as much detail as you can, I would much appreciate it. Thanks for the help in advance <3