Dell Latitude E6440

I am going to get a new laptop soon and was thinking about getting the Dell Latitude E6440 (more specifically, the one with the i5 and AMD Radeon)*. But first I'd like some opinions on the upgrades I intend to make if I get it.

I would be using this laptop for some light gaming, coding, and schoolwork, as well as the other general uses of computers (watching videos, listening to music, etc), so it needs to be somewhat mobile. In order to achieve the best results out of this laptop, I would be upgrading basically everything that can be upgraded. But before I decide to make the dive and buy all the necessary hardware, I want to make sure they would be possible and relatively simple updates.

1. Processor - Status: Unrated
I was going to upgrade the laptop to an Intel Core i7-4810MQ quad-core processor. I understand that the larger heat sink that comes with the dedicated graphics version would be able to handle the extra heat output. I am just confused as to the TDP being 47W instead of the Core i5's 37W. I read on the TechInferno forums that this upgrade is possible, but the wording is unclear when it talks about the TDP. I am basically asking if I need any special BIOS or programs in order for the Core i7 to function properly.

2. Memory - Status: Unrated
I would upgrade to Corsair Vengeance memory, 16 GB.

3. Hard Drive(s) - Status: Unrated
I was going to replace the 180 GB Intel SSD that comes standard with a 180 GB Intel mSATA SSD, and install a 1 TB HGST Travelstar 7200rpm HDD in the now-free slot.

4. WiFi Card - Status: Unrated
I was going to replace the standard WiFi card with the Intel Wireless-AC 7260.HMWG card. Is this good, or would it be better to get the 7260.HMWG.R revised version?

5. Operating System - Status: Unrated
I was going to purchase Windows 8.1 Pro and install it on the SSD as the primary boot drive. In keeping with current technologies, and to increase boot times, I want to format this drive and set the BIOS as UEFI. If anybody has anything helpful about configuring a system to use UEFI (as well as taking advantage of features like adding the Windows product key to the BIOS) please let me know.

Any help would be appreciated! I will put a status next to each upgrade to show if it has been approved or not by the community.

* The only difference, after the upgrades, between the i5 and i7 with dedicated graphics is the ExpressCard slot, and I don't think I'd ever use it. So why not save the money? (And if it really is important, I can retrofit one.)

EDIT: I can actually get all of these updates (except for the hard drive/solid state drive), factory direct from Dell, by just getting the Precision M2800. The outside of the case appears the same, except for some port rearranging. What should I do?
(But, of course, this is a laptop that needs to be fairly mobile since it is for school, and the Precision M2800 only comes in a 15" screen size.)