Upload & Sell: On
I have had or have no fewer than five contenders here. You sound restless, PM, a surefire symptom of GAS. lol.
Better still, all these are what might be called 'character lenses' and most are older, there is a lesson there maybe. FWIW, I currently use the CY 100/3.5 Michael mentioned, regard it as 300 grams of solid reliable greatness - re colour, flatness of field, accuracy and surprisingly bokeh, very nice for portraits.
But you can't go wrong with those listed above, so maybe do a Bifurcator and check 'em all out. I just checked out a suggestion by the very knowledgable rico - Leica M 135mm f4 Tele-Elmar, but alas no adapter available for Sony A mount.
Leica Tri-Elmar-M 135mm f/4, the older 1965-90 pre-APO version. Never really popular and like the 100/3.5 CY an aficionado's lens, and a little heavy at 550 grams, but I have seen some very special images shot with it - sharp but liquid, it would have been a great match for the a99 sensor. They are a bargain most likely due to the unpopularity of the FL for M r/finders (hard to focus) and cashed up L folks preferring the newer APO vsn. Well worth a look.