I might be mistaken, but as far i know most solid state amps present as low as a 10-20k load to the DAC so i don't see that being an issue.
As for resistor choice, i've all ways used the Dales as i find them transparent, certainly whenever i replaced generic brands with them there has always been an improvement. Doesn't seem to matter the wattage rating, i.e. RN55, 60, 65, of if they are mil spec or industrial range CMF vs RN as they all perform just as well.
Only other boutique brand i have tried are PRP (the bright red ones), and i didn't like them as much. I got the impression they were smoothing over the sound a little, or maybe the Dales have just become my norm.