In the following we review the optimization for microsatellite deployment of a highly integrated payload suite comprising a high resolution camera, an additional camera for stereoscopic imaging, and a single photon counting laser altimeter. This payload suite, the `Stereo Imaging Laser Altimeter' SILAT has been designated for deployment aboard the FAST microsatellite formation mission for Earth observation. This instrument suite has been designed for a Jupiter mission, but has been redesigned and optimized for an Earth observation mission. This paper reviews the simulated Earth observation performance, the design modifications made for the mission and the optimization of the design for microsatellite use. Mass and power budgets are used to demonstrate the changes and the performance analysis is represented trough the simulation results. It is expected that the optimization will reduce the mass of the instrument by approximately 20\% without compromising the performance of the instrument. In addition, results from breadboarding experiments of individual instrument components will be presented to show the progress from design optimization towards the FAST flight model.