Critical stuff is the input voltage and component DC resistance. The input voltage should be the unloaded voltage measured when line voltage is applied and the winding in question is otherwise unloaded.

DC resistances of just the secondary have been acceptable. With the step-down ratios encountered with filament supplies, the small primary resistance appears even smaller.

The ESR of the capacitors seems to make very little difference. The data is either available from the manufacturer or guess. Tens of mOhms to a tenth of an Ohm seems to be a reasonable bet for a 'lytic. Go for the minimum allowable for good film caps.

regards,
Douglas