Go with 3x 8bit 70ns flash. Your only addressing the first 512 words, the memory wont even swap a page, your output will be clean and fast.
The forementioned bit glitching should be ignored if the data output is feeding a clocked logic gate or clocked dac as the data is only sampled on the leading clock edge after once it becomes valid.
Note that 16bit proms still exist and are also in the 1-2$ range, but you cant's erase and reprogram them if you make a mistake. The authentic eprom versions, basically a ceramic case with the eprom window actually costs around 350$. Yes, 349$ for a glass window!!! (What on earth?)
Just use the oversized Microchip 128k x 8 eprom compatible which is a 32 pin dip, 2$, 70ns, 8 bits, arrange your data in you programmer's memory editor to fill only the first 512 words with the upper & lower 4 of the 8 bits with your prom's contents and hand wire 3 adapter boards for the 6 proms.
On your adapter, remember to tie all the unused addressees to GND. Double check the chip enable and output enable.
Ohhh, looking at the circuit board, I see a resistor DAC.....
You might want to add a SN74ACT574N (+/- 25 ma/pin VS the eprom +/- read the spec) on the data outs and find the common clock to drive the 574's clock in. Keep an inverter gate handy in case you need to inverse the clk signal. This should give you a clean strong bright picture. Driving the resistor DAC directly from the eprom wont look as good because of low power source and sink outputs.
You can try unclocked buffers like the SN74ACT245N, or 74LS574, or it's unclocked equiv. This will alter the picture characteristics since the sink and source currents through the resistor divider will affect the picture. Clocking the eprom will create a clean data output delayed by 1 pixel, but, no glitching introduced by the internals of the eprom.
Without the output buffers, the eprom has a 2v high logic level. However the 82S131 has a high of 2ma, a sink of 16ma.