I know that the title above is quite confusing because I don't know myself how to categorize the type of metal I'm looking for.

I'm basically looking for albums which sounds like:

Amorphis-Tales From The Thousand Lakes
and
Orphaned Land-El Norra Alila.

Avoid recommending Gothenburg style melodeath (At The Gates, Arch Enemy etc...)
Avoid recommending just plain doom albums (Such as old Katatonia or Paradise Lost)
And avoid recommending just prog metal, because it isn't what I'm looking for.

The most important characteristics of the albums I mentioned before (El Norra Alila and Tales From The Thousand Lakes) are these fluid type of melodic and heavy riffs, the complex structures and the easy flowing of the songs.

I don't know how to describe it better than that, I think that people who listened to these albums deeply enough will know what I'm looking for.

Thanks in advance

I'm guessing you like edge of sanity then, right?

Solecism! They're a very progressive melodic death metal band with noticeable doom influences. I wouldn't say that they're a death/doom band, but they have moments of extreme doominess, particularly "Slave." You should definitely check them out.

You might enjoy Novembre. I saw the title and the first band that came to my mind was them. They definitely use doom elements with progressive elements and a nice sense of melody. I'd recommend their latest, The Blue, it was a great album to say the least. Not sure if they'll have a strong enough death influence for you though. Yet, I feel they meet your description of strong melodies and heavy riffs with a flowing organic quality.

You might benefit from checking out the Russian band Ekklesiast, I've got their Holod (Cold) album, it's got an interesting mix of tempos and the drumming is fairly convoluted at times. There are plenty of acoustic passages, the vocals are straight up growls with infrequent female backing vox. It's not overly cheesy nor hard to listen to, give it a shot..

Do you mean Solecism from Chicago? I just played a show with them a few days ago. They're really good!

Yeah, that's them. Also, I was at that show; I was helping them move their equipment up there. Which band were you playing in?

Visceral Evisceration! (If you don't mind gore lyrics)