I recently acquired a second hand set of Wharfedale Opus 2-M2 Bookshelf speakers that I very much enjoy. Noting that the Evo uses a similar, but smaller, soft dome midrange, I would have some confidence recommending the superb Legacy i.V2 (which I undesrstand has the same build as the i.V4 Ultra, which I reviewed for Dagogo.com).
If I were in your situation, I would use the potential stepping stone of having separates to move to a typically much higher level of sound quality by staying with separates and upgrading them. I would use the Arcam pre and get the Legacy amp.
Having reviewed a Belles Aria pre/mono amps for Dagogo.com, I believe the Aria integrated would probably be quite nice. Another recommedable option would be the Kinki Studio EX-M1+ (or whatever version it is now), which allows for rolling discrete opamps that can fundamentally change the character, allowing for a wider pallate of sound to tune it to the system. I rather enjoy that and find the Staccato opamps to be superb.
I know of no other integrated amp that offers the configurability of the EX-M1+. You can use it as either full integrated, dedicated pre or dedicated amp. That would give you, along with opamp rolling, a tremendous number of options to simply enjoy variety of systems. But, if your goal is to ultimately move beyond it closer to SOTA, then I would go with the Legacy amp.
I realize my recommendations are above your price point, but I assure you that they are very worthwhile selections and you would simply need to save up more to acquire them. Do not doubt the efficacy of that choice. The performance spectrum is enormous and your current system is not near the outer edge. I do not say that with contempt or disdian, because I was a budget audiophile prior to reviewing. I am teling you with certainty that more money put into it will nearly beyond a doubt yield a much better result. At the lower cost end of the spectrum especially, a thousand or two can be a substantial differnece in products’ performance. The use of better equipment won me over such that I became willing to spend much more to attain a superior performance level and much more enjoyment in listening. :)
For other members, I have no interest in debating my recommendations and methodology.