Regarding my budget, I can spend 2-3 k if needed but if possible would like to make a good use of my iPad first and get some value of what I paid for it
The good news is that, with only needing 2 mic inputs, the interfaces available to you for the iPad will likely have that many inputs.
The best one is the Apogee duet: $600 Apogee is a popular name in the audio world for having such good converters. While there is a mic located inside the duet that’s actually pretty decent, if you want the best sound, you’ll need to buy your own separate mic with it. I think it only uses a 30 pin connection, but I’m pretty sure you can buy one of the cables they sell that will allow it to work. This can also be used with PC or Mac should you choose to switch to PC.
Another decent option is the iRigPro Duo: $200 same functionality as Apogee; just no mic inside the device, and the converters are not as high quality, though if you have no decent studio monitors and haven’t trained your ear to these differences, may honestly not even tell the difference between the two converters to shell out the cash for it. This can also work with PC or Mac shoudld you choose to switch.
There’s certainly some others I’m forgetting about.
Honestly, if you want to forgo the MacBook, the best option would be the Apgogee and a good mic to go with it. But you should listen to some recordings using these interfaces on YouTube and judge if it’s worth the money. One thing you should know, though. The peopl with Apogee interfaces will probably have much better sounding recordings because people who have invested in those interfaces are dedicated to getting good audio and having good mixing skills. Just know that, if the difference between the recordings of the two devices seem huge, they might not be as big as they might lead you to believe because of the whole mixing process going on.