The following two are very old recordings on LP, but they are revered as the best interpretations. They have adequate sonics, but of course, they are not modern recordings amd were recorded on mono as they were recorded before the stereo era. Rachmaninoff was noted for his skills as a pianist and not only as a composer.
I can recommend the RCA Album, a 3 record set, RCA ARM3-0296 MONO. These include his Four Concertos as well as Rhapsody on a Theme of Paganini with Rachmaninoff at the piano, The Philadephia Orchestra, and Eugene Ormandy on the concertos and Leopold Stokowski conducting on the Rhapsody.
The next revered interpretation is with William Kapell the pianist with the Robin Dell Orchestra of Philadelphia and William Steinberg conducting. The young Kapell perished in an airplance accident shorlty after. This record is RCA LM-1097. Much praise has been given to this version. The version of the second and third concertos with Byron Janis as pianist, Antal Dorati and the Minneapolis Symphony Orchestra in the 2nd and 3rd concertos also has much following and praise. The numbers for the stero version of the 2nd concerto are Mercury SR90260. I think that the versions with Horowitz as well as Rubinstein played at their peak years also deserves listening. They both have many recordings spanning perhaps thirty years and you should listen to which you judge to be the better or best versions. I can recommend the Rubinstein/Reiner/Chicago Symphony version RCA ARP1-4934 touted as as Audiophile Pressing manufactured on TELDEC vinyl recorded in Orchestra Hall, January 9 and 16, 1956. This recording is of the Concerto No. 2 and the Rhapsody on a Theme of Paganini. Richter and Van Cliburn also have credible interpretations.
Happy listening. Please give us some critique and feedback.