Can I swap the r1 motherboard for the r3 motherboard?

No, the R3 has a different port layout and appears to have a different heatsink location. I've never personally owned both the R1 and R3, but Dell Forums suggests that there are a lot more incompatibilities than just the ports. I suggest the Eurocom Monster 1.0 if you're looking for a new 11" gaming computer, it has a lot of options, even server level processors with the i7-3 Extreme CPUs and up to 8TB storage, all packed into a sleeper netbook look that won't get your laptop stolen at a Starbucks. Besides that though, you're better off reselling for parts on eBay and buying something even newer than that.