Sup guys im new to this but i need some help with a song im writing.
I made a chord progression and it goes:

Gmaj7 B7 A7? D7
2 2 3 2
0 0 2 1
0 2 2 2
0 1 2 0
2 2 0 x
1 x x x

So my problem is im trying to write a lead or solo to it but im not sure what scale to use. and im not even sure if the chords can go into a progression together, i mean it sounds good to me but the notes that are in the chords itself dont go in any scale together. Can someone please explain to me how these chords go together(if possible) and a brief explanation of how to solo over major 7th chords and dominant 7th chords in the same progression? ive been using the E natural minor scale to solo over it but i want to kno more about the theory side to these chords and how they can go together.
P.S. i want to make the solo kinda mellow and melodic

Thank you, Josh