From IRAS data, we have identified a possible correlation between QSO FIR spectral energy distribution and host galaxy morphology, which, if confirmed, may be important in understanding the evolutionary history of the QSO phenomenon. New ground-based observing techniques and the refurbished HST are producing detailed images of QSO host galaxies. Many of these images show features that broadly support interaction and merger scenarios for the origin and evolution of quasars, including double nuclei, bridges and tails, and previously unsuspected close companions. We find that, of 34 QSOs detected by IRAS at 25, 60, and 100 microns, the 3 that fall close to the region of the two-color diagram occupied by the ultra-luminous starburst galaxies are also the only 3 QSOs in this sample showing convincing tidal tails. By using ISO to obtain photometry on a complete sample at higher redshift than was possible with IRAS we will be able to test this apparent correlation. Our sample comprises all quasars with 0.5 < z < 1.25 from the 3CR and Peacock-Wall surveys. We currently have deep ground-based optical and near-IR imaging of a significant portion of the proposed sample, and we have scheduled HST Cycle 4 time for imaging several of these quasars.