Seems I'm mentioning these to a lot of people lately... probably because I'm contemplating one for myself in the near future. For a highly-portable powerhouse, checkout the Alienware M14x.
Start with the lowest priced model and upgrade from there (stick with the 4GB of RAM from Dell, upgrade it yourself later from somewhere like NewEgg.com).
The only place this might miss the mark for you is that it has agressive cooling, which means fan noise when you've got the GPU cranking, but you'll have some amount of that with any machine with these specs crammed in such a small unit.
I just configured one on their site:
Alienware M14x
Genuine Windows® 7 Home Premium, 64bit, English
Intel® Core™ i7 2670QM 2.2GHz (3.1GHz w/Turbo Boost, 6MB Cache) ($100 upgrade from i5 2.4Ghz)
Intel® Wireless-N WiFi Link 1000 a/g/n 1x2
4GB Dual Channel DDR3 at 1600MHz (Upgrade this yourself later, if needed)
1.5GB DDR3 NVIDIA® GeForce® GT 555M using NVIDIA Optimus™ technology (upgradable to 3GB for $100, if needed)
500GB 7200RPM SATA 3Gb/s
14.0" High Def+ (900p/1600x900) with WLED backlight (upgrade from std 1366x768)
8x SuperMulti DVD±R/RW Slot Load Optical Drive
2x USB 3.0 ports
Internal High-Definition 5.1 Surround Sound Audio
Internal Bluetooth 3.0 ($20 upgrade)
Alienware M14X 150W A/C Adapter
$1294 (before shipping/tax).
I also like the ASUS units for a workload like you describe, but they are definitely not anywhere near the "ultra portable" size... my 15.6" ASUS is the same size as certain 17" models... I love it, but it's LARGE.