Installing Himalayas/Mt. Everest scenery into FSX. Help needed please.

Hi. I bought Aerosoft's Lukla scenery for FS9 when it first came out (I had just come back from Lukla real-world at the time - a great experience: the sloping runway was still being constructed when I was there, so I flew in by helicopter: spectacular, to say the least). I didn't subsequently get the FSX Lukla X scenery as I rarely flew FSX, but now that I have sorted out problems with viewing FSX on multiple monitors, I fly it more often and have only  today installed the FSX version.

I see however that there are various freeware additions to this which work with the Aerosoft scenery and certainly look wonderful from the various screenshots, but I am not 100% sure which is compatible with which - I hope someone can advise.

OK, so as I say, I have installed Aerosoft's "Lukla X - Mount Everest". I already had Frank Dainese's Mt. Everest HighRes Mt. Everest scenery installed (Everest 1.bgl through to Everest 10.bgl, dating from 2008).

I discovered  the same author's later HighRes Everest scenery, here:

http://simviation.com/1/search?submit=1&keywords=Frank+Dainese&categoryId=63

(files there continue onto a second page)....

Then, there is also this:

http://www.realearthx.it/site/prodotti/free-scenery.html

also by the admirable Frank Dainese.

I just want to check what I should install. I am assuming (please correct me if I am wrong of course) that:

1. The files that relate to Mt. Everest at the simviation.com URL above (EverestP1.zip & EverestP2.zip) are just duplicates of the files Everest 1.bgl through to Everest 10.bgl that I already have. However, from the realearthx.it site I now have a much larger (and later) set of Frank's bgl files relating to Everest (1Everest_Frank.bgl, 2Everest_Frank.bgl etc.). No doubt I need to remove the Everest bgl files I already had installed from EverestP1.zip & EverestP2.zip (Everest 1.bgl through to Everest 10.bgl). Both sets of files are Everest scenery files and so mutually exclusive, right?

2. I assume however i can download and install all the other non-Everest Himalayan scenery from the simviation URL above site, "Nanga Parbat, Karakoram Range", "K2 Detailed Mountain Scenery", "Broad Peak Mountain, Karakoram Range" and "Makalu Mountain Scenery, Himalayas"...

3. Mesh: The sceneries recommend installing Holger Sandmann's Himalayan mesh from the AVSIM library (and the simviation URL above, plus probably dozens of other sites too), which they say works just fine in FSX:

http://library.avsim.net/search.php?SearchTerm=Himalayan+Peaks+LOD10+Mesh%2C+Volume&CatID=fs2004&Go=Search

but I already have a full set of FSGenesis FSX Terrain mesh installed. Is there any benefit to having Holger's mesh over and above the FSG files?

I think the answers are relatively obvious, but I'd like to check what others have done (and maybe, having spent some hours looking into what is available, this thread may  be of interest to some who didn't know of the availability of all this nice mountain scenery).

Also, what order for all this in the FSX scenery library?

Thanks for any clarification.

Martin