What are some good resources(courses,books etc) to craft a comprehensive and sound repertoire for white centered around E4, for a player of intermediate strength (2000 chess.com rapid)
At this point in my career, I use Chessable for all my chess book needs. There are many GMs and super GMs that have published their lifetime repertoires.
Gustafsson's has a good one,So has another good one, but there are many more to choose from. I also use Chessbase to keep my openings straight and practice them.
To have a full repertoire for e4, however, you are going to need a lot of opening prep. There are many responses to e4 and you really have to have a response for all of them.
I like Attacking with 1.e4 by John Emms, Everyman Chess, 2001. It recommends the closed variation against the Sicilian, the Bishop's Opening against 1...e5, the King's Indian Attack against the French, 2.c4 against the Caro-Kann, the 150 Attack against the Pirc and Modern, and it covers the Scandinavian, the Alekhine, and a few others too.
There's also Chess Openings for White Explained by Dzindzichasvili and others if you want a big, detailed book. I haven't read most of it, but I know it advocates playing the Scotch Gambit.
I'm sure there are many 1.e4 repertoire courses at chessable.com (though I don't use the website).
You could also use a database like at lichess.org to build your own repertoire.
Have a look at the Openings for White according to Anand series by Khalifman, it goes through all the best answers against e4, which means all the main lines are covered from White's perspective. It's been out for a while, so it's a guarantee that some lines will be outdated or have some holes in them, but it is a great resource.
Be warned, though, there are 13 books in the series. That the difference between playing main lines, vs offshoots that can fit into one volume.
You could reduce the workload by changing some lines, i.e. Italian instead of Ruy Lopez or Gran Prix attack vs Sicilian, and just get the rest of the volumes to deal with the likes of the French, Alekhine etc.