New gaming rig with Vista OEM questions

Okay I'm hoping the thread description is somewhat explanatory as it pertains to what I'm trying to accomplish here...

So I just plunked down about $1200 on new components to upgrade my system. I'm basically replacing every core piece of hardware in my case: mobo, CPU, RAM, video card, and PSU. When Vista released last January I purchased an Ultimate OEM disc. Arguably foolish, granted, but I wasn't really planning on upgrading for awhile as it is and wanted to play with all the new Vista stuff without paying an arm and a leg. The computer I have now is dual-booted with XP and Vista (XP so I can still play games without most of the 1024mb of RAM being hogged...)

I suppose I'll first breakdown what is going inside the case and then get to the questions:

Motherboard
Asus Maximus Formula II
replacing Abit KV-85 (VIA K8M800)

Memory
OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR2 1066
replacing 512mb x2 ddr PC3200

CPU
Intel Core 2 Quad Q9450
replacing AMD 64 3000+

CPU Cooler
Zalman 9700 LED
replacing stock cooler

Power Supply
Thermaltake W0131RU 850W
replacing Antec 430W

Video Card
Visiontek Radeon HD4870
replacing NVidia Geforce 6800GT

So does anyone want to take guesses to determine how many years I've been using my current rig? Now that I'm upgrading though I certainly would like to hear how everyone thinks I did regarding part selection. I spent a lot of time researching and changed my mind many many times and am hoping that this will last me at least as long as my current one did. The parts have already been ordered so it's a tad late to tell me to switch (Newegg may take them back but that's a hassle and a half), but it's certainly okay to tell me I screwed up so at least I know.

I can explain what my goals of this setup are so that we're on the same page. Basically, to be able to play current FPS games without sacrificing visual quality settings by much (with the exception of Crysis, of course). I have a 22" monitor that sits at 1680x1050 default and that is where my resolution will (ideally) sit at all times. Additionally, I will be using it to play music and use productivity software like Office and such. So, how'd I do overall? Will it perform at this resolution in most current games?

Will there be any noticeable device conflicts? I checked ASUS' QVL for the memory and I'm pretty sure it was listed (just in a different capacity, but I don't think that matters). Everything else should be fine to the best of my knowledge. Am I on the mark?

Will overclocking any components really be necessary? I can certainly do so later down the road as the need arises, but is it better to do so in the beginning and get it out of the way?

This is a big one. Will I need to do a fresh install of vista? Will just swapping out the components and turning the system back on boot into the OS alright? This question has two sides though. Will I need to complete a fresh install because of how significantly the devices are changing (and Vista will get all screwy if I don't), or will I have to because it is an OEM install and the changes are too significant for Microsoft to allow? If Vista cannot auto-activate (assuming the computer boots in fine and such), will calling Microsoft be of any use to try and get it activated? Basically, I'm trying to avoid another $200ish to buy a retail Vista copy.

On the flip side, will I want to do a fresh install? I usually have done so every 1-2 years on my current computer with XP but doing so now would be more bothersome since I am back in school and would need to backup a lot of files to make sure everything is in order before wiping the HDD. I am going to get rid of dual booting and remove the other HDD that I have XP installed on since I only used XP for gaming

Now that I have tossed out questions all over the map, I give the floor to whomever would like to chime in.

Thanks

i really do think you should do a fresh install of vista on your new computer, you don't want any driver conflicts

and 1066ddr2 is kind of waste unless you planning to go past a cpu speed of 450-500...which will be hard with a quad O_O, but i guess as long as you pass 400mhz, its not a waste... assuming you plan on overclocking

everything should be max or close to on your 22", so you'll be fine... but do yourself a favor and fresh install of vista, i wouldn;t know if the OEM will cause problems though

I have the X3350 @ 3.6 (450X8) on air with a Zalman 9500, The RAM you got is right on. Because If you had got DDR2-800 It may not overclock to 900.

You should be able to do 3.6 with the Zalman 9700 as long as you don't get a crappy chip.

I do like your rig, The only thing I would have changed is the motherboard if you plan on Crossfire with the X48 Chipset.

You should do a fresh install, If you were going form lets say a Intel Chipset to another Intel Chipset or VIA to VIA then you might not have problems with a swap and install drivers. The system may crash and crash if you try to keep the installation of XP or Vista, or you may get lucky.

No matter what you will have to reactivate Windows when you change your hardware. The question is do you want to activate twice in one week or only once? The reasion I say that is within a week you may reformat due to crashing.

Have fun with your new rig

1Haplo