In need of a new compooter (probably)

Gah. It's only been a week and the nerves are starting to crumble.

Was quietly levelling up my new Pistol-packin' blaster (yeeha!) Saturday morning with a lovely cuppa when my comp froze with a sound loop. Odd.
Rebooted, came back up, back in game... same thing.
Rebooted... lots of visual artefacts... NVidia driver dies but comes back up... then BSOD.

Uh oh.

And when I finally get it back up in Safe Mode, the screen is cluttered with random visual junk, and Device Manager can't find my card.

So my shiny laptop is now in the vet's, but I think it might be time to put it out of its misery.

WHAT I'M AFTER:
1. Something that can run Final Cut and/or Photoshop, DW and a couple of server interaction apps at a decent speed and with plenty of layers & windows active, as this is my stock in trade.

2. Something that can handle the current generation of 3d games without keeling over or burning a hole in my desk. Ultra Mode would be nice but I've never really been fussed, so long as I can still play. In my mind, this means Dual Core, NVIDIA gfx card and at least 3 or 4 gig of RAM. HD space is totally irrelevant.

3. I'm not fussed about brand names or looks. BUT I do want one with an actual, walk-up customer service place that I can walk up to and [ look piteous/rant/flirt shamelessly - delete as necessary ] until I can get it fixed.

4. The words "customer service" and "PC World" are mutually exclusive. John Lewis is great, Dixons and/or Currys ok, or any decent store within Central London or 50 miles of Norwich.

5. Ideally a laptop, but still one with swappable parts/PCI-E rather than everything glued to the chassis. I do travel for my job quite a lot - and while I don't work well on trains or in taxis, hotel rooms are fine and dandy and it's good to be able to work out of a client's office when necessary.

6. Preferably spending less than £800.

7. Yes, I want fries and a calorie-free double chocolate muffin with that.

Two I've been looking at as examples:

LENOVO G550S
Intel Core 2 Duo E6600
4GB RAM
Nvidia GeForce G210M (512mb dedicated)
Win7
£550

ASUS K50IN
Intel Core 2 Duo T6500
4GB RAM
512MB Dedicated NVidia graphics (exact card not specified)
Win7
£570

Thoughts and/or tips would be appreciated. Particularly from poor Damz, who illustrates one reason why I'm terrified of mail order for anything this big and/or delicate...

...the other is that I used to sort at Royal Mail when I was a student. Having someone stage diving and/or jumping on trolleybins full of packages to get them to fit on a lorry deck does not inspire confidence.

Spend a bit more and get one with a decent graphics card.

The problem is both quality and value rarely go hand in hand with retail chain in the computer world. YMMV of course.

PC World is only good if you know what you want, their customer service is crap.

Best thing to do, wherever you got, just lay your required specs, act like you're going to pay cash (and then don't) and see what they can do for you. Don't let them push you over budget. You should be able to get a decent enouh laptop for your budget