80/2.8 HFT Planar 2.8/80 80mm f2.8
Most of the time when you get a SL66, SL66E or SL66SE, the body will come with the 80/2.8 standard lens. And straight away you will be able to do a lot of wonders with this basic set up. In fact the SL66 body cap (you will need one if the body does not come with a lens as a set) and the lens rear cap are very rare items and can be expensive.
I have a 80/2.8 Planar that comes with my SL66, and the 80/2.8 HFT Planar with the e-ring for TTL metering with SL66E in the above photo. This is a versatile lens, being a standard focal length good for many photography purposes, with the bellow of SL66/SL66E/SL55SE it can anytime be used in the macro mode, and for high close up magnification the lens can be reverse mounted without extra accessories and becomes a high quality macro package.