Welcome, and congrats on this opportunity to build system that you enjoy!
Doing the math, it looks like you have established the following budget for a complete system with digital source:
- Digital Transport: $2.7k
- DAC: $4k
- Amplifier: $1.7k
- Loudspeakers: $3.5k
Assuming that the goal is to build the best sounding, nice looking, and most enjoyable to use system possible for $12k (optimize for value for money), experienced system builders may spot some weaknesses in this allocation of funds.
First, if you’re going to be using Roon exclusively, you don’t need the Aries G1 if you have the Vega G1. The Vega G1 is already a Roon Ready device, so the Aries adds no value, unless you plan to use it in a 2nd system in front of a different DAC. I see no advantage in using these two components together.
Over half of the budget has been allocated to the source. Now, the source is certainly important, but digital technology has become really good over the past few years. The difference in performance between a $800 DAC and a $4,000 DAC is vanishingly small and would require a tremendously resolving room with more resolving loudspeakers than $3.5k can typically buy to detect, much less appreciate.
The other problem with allocating 55% of your budget to digital components is that these things change very quickly. Digital gear ages about as well a smartphone. Software, formats, standards and apps change really fast, so it’s difficult to imagine that you will be using the same streamer or DAC five to ten years from now, but if you choose wisely, it’s reasonable to imagine that you will be using the same amplifiers and loudspeakers in ten years.
If you’re familiar with digital photography, the same idea applies. People new to the hobby tend to get over-excited about the latest camera bodies and features and over-spend on their first camera body while under-spending on lenses. If they stay with the hobby, they realize that it pays to invest in glass since a good lens can last 10+ years and will outlast several generations of digital SLR bodies because tech changes so much faster there.
There are no hard rules, but spending roughly twice as much on loudspeakers as on amplification feels about right in this price range, so to optimize for long-term value, you just need allocate a higher percentage of your total budget to these bits that will likely stay in your system the longest. For example, roughly $6.5k on loudspeakers, $3.5k on amplification, and $2k on a digital source is likely to produce a system that substantially outperforms the components you have been considering.
If you really like Martin Logan, go with their Masterpiece Series instead. ESL 9 or ESL 11A if you can stretch a bit. The 11A can use ARC (Anthem Room Correction), which could make a big difference in the sound in your room. These run around $7k, +/- $1k for a pair.
The ESL 9 or 11A would be driven nicely by the robust Parasound Halo Hint 6 integrated amplifier for around $3k. The Wyred 4 Sound STI-v2 is about the same price, depending on options.
For your digital frontend, consider the Chord Qutest or Benchmark DAC3 B for around $1.7k.
You can Roon-enable either of these with the USBridge Signature Player or DigiOne Signature Player from Allo.com. People tend to think of Allo as a DIY company, but their Plug & Play products really are plug & play…they arrive fully configured with Roon and ready to go; just add an Ethernet connection. If you really must have Wi-Fi, they provide ways to make that work, but a wired connection will almost always be more robust and is worth investing in if you possibly can. These are top performers, but the investment is minimal, so if better stuff comes out a couple of years later, you can just toss them in the recycling bin without much remorse vs. having to live with a $2.7k doorstop.
Not the direction that you had in mind, but I hope this is helpful. Ping me if you have questions.
Update: I heartily agree with everyone here who has pointed out that spending some money getting the room right lays an essential foundation required to fully appreciate a ~$12k audio system. I only have a little over $1k invested in room treatments (a combination of ATS Acoustics and GIK Acoustics) for my 15.5 x 10.1 ft listening room, and the difference they make is beyond dramatic.