THS3491 looks like an interesting op-amp for distribution amplifiers and in general for LF/HF work. However it turns out it is a bit finicky about the feedback resistors (high resistance values are stable but noisy, low values would give low noise but might be unstable). We're sticking with LMH6702 for now..
Some old plots from 2017 of the residual phase-noise at 10MHz when the signal is fed through an SMA-to-SFP board, SFP to optical, 2m optical fibre, then SFP back to electrical, and another SFP-to-SMA board.
One version of the board is on github: https://github.com/aewallin/SFP2SMA_2018.03
As a comparison the noise-floor of the 3120A and a frequency distribution amplifier is also shown.
Have been using this SMD heatsink for (among others) TO-263 voltage regulators, e.g. LT1963 and LT3015.
These 'plain' footprints correspond to the "land-pattern" footprints created previously. No GND-pads or GND-vias in these.