Fighting the KID

You might want to work on not dropping material, not missing simple tactics, and not following opening principles.  Or...you can work on openings, and still do the 3 things i mentioned.

First of all, the advice of @IMBacon is absolutely correct. However, to actually answer the question:

Looking at your games, you seem to like the London System so why not just play that? It can be played against 1...d5 and 1...Nf6 (but not other moves). However if you want a mainline then the Makagonov System is what I recommend:

The idea behind this setup is that white will want to play g4 at some point, preventing black's classic break with f5. White will then castle queenside and can push pawns against black's king on the kingside.

If you want something more quiet then the Exchange Variation is the way to go:

Playing this could help improve your endgame skills.

Thanks @my137thaccount

On what basis is the KID the 'strongest'? Yes plenty of great players have used the KID, but plenty of great players have used the Grunfeld, Slav, QGD and Nimzo-Indian. Also, why do you think white will be 'blown away' in these lines? Possibly with the exception of the London System (and even so I don't think it's an exception) all the lines I mentioned are slightly easier to play with white, simply because white goes first. Playing the Classical Variation or the other ultra-theoretical lines however is the way to get blown away by KID experts who have spent decades analysing them.

What we need to keep in mind is this...

The OP is rated under 1400.  I doubt he will be running into any KID "experts"  Basically..it wont matter how well/bad the opening is played.

The OP doesn't follow Opening Principles, misses simple tactics and hangs material.  None of which will be solved by studying an opening.

KID is for the brave as London is for the meek. I'm probably the lowest rated KID/ Gruenfeld fanatic. But ImBacon is right. OP should not fear KID refutation. And simply master the basics of chess.

I think it is reasonable to hold that the KID is a strong defence. I think its strength comes from its incredible flexibility and variety of possible plans coupled with resilient protection for the king.

I would not recommend to go for that without proper preparation. My coach also told me that every now and then lower rated people want to go for an easy draw with white and try the exchange variation. You need to know the basic strategy behind that. Otherwise you are simply lost in an even position. Vigorito says the same in his KID book (vol. 1, chapter 13)

I loved this one article from some years ago which gives you an insight in the features of the structure:

https://www.chess.com/article/view/the-kings-indian-exchange-structure

For me this one article saved some points already (for black) as white players of my rating mostly think that they can finish preparation after Qxe8 and go for the draw. And I always had the feeling that it plays easier for Black.

Concering the Saemisch you need to try. I did some thematic tournaments here at chess.com on this and I have the feeling that (for me) it plays badly for Black and White and I never got a hold on it.

Final recommendation: Go through the variations of your choice, get some feeling if a variation fits to you and start a thematic tournament (KID themes are easily filled with participants) and see if it really fits to you. Here you also get a feeling for the other side and learn about the challenges on both sides.

Yeah, the common wisdom is that the Exchange Variation is nice for black, but I think things are not so clear cut, and someone who specialises in it, e.g. studying games of Ulf Andersson, can have very good results in it. White keeps a slight initiative, which he can use to aim to push the pawn to c5 putting pressure on black's position - Andersson games make it seem like an easy win for white, although obviously black can equalise with correct defense.

I fully agree with you! The thing I wanted to stress is that (for both sides) the one who puts on a better massage will have an advantage. This also implies that you have to be prepared for subtle features.

Experience420, who started the thread, didn't make the impression to me that he is looking for a line which takes quite some knowledge after the opening moves in order to get something out of it. Because otherwise you watch the opponent for many moves how he improves slowly a position you don't understand and loose later on after a completely frustrating and boring game.

When thinking about my own preference I would go for either strategic Petrosian variation or a tactical Bayonet attack. With better knowledge I think the Gligoric system has a lot of interesting games but there are too many posibilities for Black to chose from.