All components impact the quality of a system, however with a vinyl system, the two transducers, speakers and cartridge, have the greatest impact on the character as well as the quality. Since you already have chosen speakers, I would focus on identifying a integrated amplifier that will drive them to your satisfaction, power and sonic synergy wise, then focus on the TT, cartridge, phonostage front end. My preference would be to use an external phonostage for the flexibility it would provide with different cartridges. Many are designed to match with a wide range of cartridges regarding gain and loading. Of course if you purchase a integrated with phonostage, an external one could always be purchased later. You should be able to find a integrated in the ~$1500 range (the Rouge and NAD fit this) leaving a larger budget for the vinyl front end.
Thought you don't want to short the Maggies on power, your listening volume levels and room size make a large impact on actual power requirements.
Thought you don't want to short the Maggies on power, your listening volume levels and room size make a large impact on actual power requirements.