Upgrading an M1730, lots of questions?

Alright.... I'm never totally sure how to begin a thread like this, so I'll start with the basics. Back in June I managed to score an M1730 off of Craigslist for an unbelievable price... less than I've even seen similarly configured ones on the Dell Outlet go for, and I even managed to get it in my favorite color(Sapph. Blue). The specs are as follows:

T7500 C2D processor, 2.2Ghz
8700M GT graphics card(base, non-SLi)
1x 320GB HDD
2GB RAM
PhysX PPU(for all the good that it really does, so I've heard)

Now, I love this notebook to death. Even with the weight I'm completely happy with performance as it sits, and with what I will be using the machine for mobility is not a primary concern. However, I will be using this machine as my primary computer when I head back to school next year, and since I will soon become a fairly broke college student I'm going to need to throw some upgrades on it pretty soon, while I have the funds to do so. I've got a fairly good idea of what I want to do to this monster, so here's what I'm planning on doing, and afterwards I'll discuss the issues I'm running into.

-Bump RAM up from 2GB to 4GB
-Faster processor, possibly X9000 2.8Ghz if compatible?
-New hard drives; I'm experiencing a random 'click of death' with the current one at times. Either Segate Momentus 7200.3 320GB or some 5400RPM 500GB units I'm looking at. Boils down to storage space vs. speed.
-Bluetooth card?
-Upgrade wireless to a draft-n card? I've heard it is a more 'reliable' performer on 802.11g networks, which I currently run.
-New OS. Possibly Vista x64, not totally sure as of yet.

Now, I can't consider bumping up the graphics at this time... general machine performance and especially hard drive space is a little higher priority than eye candy, although I will eventually get the 8800 card when I can afford it.

Firstly, here's my question on the processor. I'm currently running a T7500, which is a Merom chip. I wouldn't mind getting my hands on the X9000, but considering it's a Penryn chip is it completely plug and play? Any BIOS flashing needed in order to recognize the processor? Will the overclocking utilities work(which isn't critical but might be nice at times)?

Hard drives are another concern. Storage space is something I need quite a bit of, although I'm leaning heavily towards the Seagates due to reliability, speed, price, and shock protection. Any advice one can give on selecting one that will last a decent while? I will probably not use RAID on the system to ensure reliability, just in case.

Another issue is the OS. I've heard many things both good and bad about Vista, and I haven't even really heard much ill spoken of the x64 versions. I personally really don't like the Vista interface, but that can be changed to the standard XP-style at the very least. There's also a major stink about SLi compatibility with these machines... has that been ironed out at least somewhat? i've also heard that the PhysX PPU has some compatibility issues with the SLi? I don't need maximum gaming performance, but I would like to play pretty much anything I can look at on reasonable settings... especially after I get my hands on the M8800. I understand I will need a 64-bit OS in order to actually utilize 4GB of RAM, and this is why I'm looking at one. I'm running XP Pro right now and generally like it, but I'm assuming that getting the 64-bit XP would be a complete no-go due to driver issues and the like. There's also the fact that I need an OS anyway, the 1730 did not come with any software at all.

The Bluetooth card is a maybe, although I have heard about lag issues while gaming. I'd definitely consider a good RF gaming mouse, but does anyone have any suggestions? The one I'm using currently is RF, but the receiver is meant for a desktop; long cord, bulky design, and all. I need something a little more portable. If I decide to go for the RF mouse(a likely possibility), is there anything else the Bluetooth card would be good for, or is it kind of a gimmick?

The wireless card is another maybe. Where I'm living there's no way to run an Ethernet cable direct to the laptop from where the cable modem sits, and since I'm moving throughout the house all the time it's really a moot point anyway. I'm currently running an 802.11g network using a pretty cruddy Motorola router; I get very low signal strength and dropout issues in my room(approx. 40-45 feet from the router). I'm considering going to a draft-n router which would make me upgrade from the a/b/g card currently in this thing. Where can I get one? Direct from Dell, or are there other sources? What will I be looking on spending for the internal card?

Are there an other upgrades or accessories that I should be looking at? I'm not totally in the dark as to what to get for this system, but any help would be appreciated. Thanks in advance!