In choosing the proper interconnect, simply note the input impedance of your specific component and choose the proper value. The cables are designed for three main impedance ranges: low (10k to 47k), for super fast solid state amps and preamps like Spectral; medium, (47k-100k) for most other solid-state and certain tube components; and high (100k-200k), for most tube components.
The Output Matched Interfaces (speaker cables) are a bit simpler to choose. There are two versions addressing either solid-state (MH-750 Shotgun) or tube (MH-750 Shotgun Tube) equipment. Both are available in bi-wired versions.