Hi, congrats on your new home and studio space. IMO a comfortable sized studio with room to change / grow / breath is great!
Responses to 2 of your questions:
MONITORS: I have Adam Audio SH3 monitors. It was a big investment for me BUT is a great step forward for my studio, mixing, mastering, etc. I had previously used very good "hi-fi" speakers for my studio. The Adam monitors make my prior ones sound like trash. The Adams are like "x-ray" hearing into a mix, it is CRAZY what I can hear in a mix with good monitors vs. with lesser monitors. So what should you get? I DO like the Adam Audio line a lot and would suggest you check out something in that line that fits your budget and space. If not the Adam Audio, then I recommend finding another solution that is well used and well loved among studio professionals (e.g. mixers, producers, etc.). A call to a good "sales engineer" at Sweetwater or Vintage Audio King can help you find a good candidate set of monitors--they know what monitors are well used and loved in studios of different sizes & budgets.
ROOM ACOUSTICS: Room acoustics are a real problem, not easily solved, and depends quite a lot on the specific room, monitors, and your objectives. There are some basic "no regrets" moves to do with setting up a room, like getting your monitors far enough from walls and other reflective surfaces. Also, bass is typically a big problem if not the worst problem in a studio; getting bass managed will help wrangle in the other issues. I have learned a lot from https://www.acousticfields.com/ and the text / videos they post. I HUGELY recommend the Reference 4 system (software plus calibrated mic); measuring your room with that AND physically measuring your room's dimensions will go a long way to identifying your problems and potential fixes. Once the Ref4 has identified some problems, IMO better to fix those with room treatments (instead of custom equalization) BUT the EQ curves actually sound pretty good these days. I would say don't expect to find a "set and forget" solution for the room, but rather some solutions and approaches which help you get better results with solutions you're willing to pay for. Example: my best guess is my current room needs $4-8k of bass treatment with units weighing over 200lbs each; I'm not willing to do that now, so I'll use Ref4 etc. to get the best out of my near-term setup.
Good luck!