I'm up and running! However, it wasn't as simple as just popping in the replacement board and being on my way...
First of all, I found the jumper on the jumper cap on my floor. I suppose the case being so small and the CMOS jumper being right next to the PCIe slot, I knocked it out while trying to force the GPU in there first time around. So the reason there was no power whatsoever at first was the missing jumper cap which was my fault.
When I went to exchange the motherboard the guy showed me that the serial number on the board itself matches the one on the box, so it was indeed a B3 version I had and was not tampered with... GerFix is correct, the rev. 2 I saw printed on the motherboard itself refers to something else. But the motherboard was definitely faulty... the guy wasted 45 minutes of my time so he could test the old board on a test bench, but he just ended up exchanging it without testing the old one (he didn't have any 204-pin memory) and thus leaving me uncertain if the motherboard was actually the culprit. So I bought some Arctic Clean and Arctic Silver to reseat the CPU and HSF on the new mobo and drove back.
I cleaned the CPU and HSF real good with the Arctic Clean which I had never bought before, always used alcohol. It works really well, it bonds to the old thermal paste and turns into a gel that you wipe off... leaves a lemony fresh scent in the case too! Then I applied some good old Arctic Silver 5 and put everything back together. But before putting it in the case I plugged everything in and tested it, it turned on by me shorting the power pins and I got the POST screen saying a new CPU had been detected and I should go in and configure it.
So I turned it off so I could put the case back together and then go through the setup. I did that and then I went to install Windows. About a minute into the installation the machine reboots and I get a CPU over temperature warning (it was at about 86C). So I think maybe I've put too much thermal paste on... I clean some of the paste off but I still get the same message. I knew there was no longer too much paste on the surface so I figured maybe the HSF isn't seated properly due to those stupid four pins Intel uses. I reinstall the HSF, but now the computer is turning on and shutting off within a half second which is new.
A while later I see that I had forgotten to unplug a molex connector when removing the PSU at some point, so the molex that connects to the GPU had all the metal contacts forced out of the plastic and therefore the video card was not getting power. I forced the metal contacts back into the plastic with some tweezers. At this point I really couldn't see
anything else possibly going wrong, so I went ahead and plugged in the front panel (minus the stupid 4-pin power LED one) into the motherboard and put the case together once again.
Guess what? It still didn't start... looking around I found out that in the three days I spent rummaging around this tiny case I had inadvertently severed a few of the cables going to the front panel. So basically the power button is dormant now and I have no clue about wiring stuff, so for the time being I hooked the reset button up to the power connector so I don't have to short it out every time. I'm hoping LianLi can send me a replacement front panel so I don't have to resort to any ugly DIY stuff for it.
About a million things went wrong independently of one another, including a totally DOA motherboard. but it's up and running now and it's quite nice. To be honest it's not blazing fast but I'm not coming from an especially slow computer, this thing isn't overclocked and I haven't really done anything intensive yet.
Certain issues still remain though. I still haven't put the PSU back in the case... the CPU already looks to be running pretty hot; I haven't installed any programs to monitor the temperature yet but the case feels really warm even though the PSU opening is wide open and one side panel is still off. The wire for the front USB 2.0 connector is also way too short so I had to remove it which leaves two open holes, but I guess some black tape will take care of that.
I have some pictures from earlier in the build, mostly showing off the tiny-ness of the case. I'll post those up when I've messed around with Le Sandy Bridge for a bit.
Thanks for all your help fellas, I'll make it worth your while...
Teehee, that's not what I mean perverts, I'm talking about spreading some reputation.