There are way too many unanswered questions here for anyone to provide you solid advice.
For example,
1) Which specific Windows applications do you need to access for work? Can they be accessed virtually via MacOS through something like Citrix, or do you need to be running Windows locally? If you can log in via Citrix, then you may not need to run Windows at all.
2) What is the primary reason why you want to switch back to MacOS after using your wife’s Dell? Are you mostly interested in the efficiency / battery life of M1, or will you use resource heavy applications that require the processing power of M1 Pro / M1 Max and more RAM? Some other reason that would provide insight into your goals here?
3) What is your maximum budget for this laptop?
4) Other than work activities, what applications will you be using on your new MacBook Pro? Photo editing? Coding? 3D Design? Data analysis? Spreadsheets? Video streaming? Gaming?
5) Do you plan to travel and/or use the laptop heavily on battery, or will it mostly be plugged in at home?
6) How many external monitors do you need to plug in simultaneously (you mentioned “monitors” so I assume it’s more than one)? Are they 4K or 5K or 6K monitors?