Five resistors seemed like too many for a 2-bit DAC (pun intended). R/2R ladders are useful because they can provide many bits using the same R's - with fewer bits, binary-weighted R's work fine. So, here's the update:

The LSB uses twice the resistance of the MSB. When both lines are at 5V, the output should be 1.4V. The output impedance should be 75 ohms. Again, two equations, two unknowns, and one computer algebra program:

The resistor values aren't that close to standard values, but 390 is good for R1 (factoring in the 12 ohms of the output driver), and 100 might do for R2. 2R1 might be 750 or 820. Or I could break down and buy some E96 values- 105, 390, and 787 would be overkill, but they're available.