For my Scorpion Carbine, presuming I don't want to use the Magpul Clip slings or a QD adapter, which HK Claw style sling setup works well with the factory setup on the rifle?  I don't like the idea of the keychain or paracord loop "adapter" part, and have no idea how the factory sling works, and am bad at researching HK style slings.

So for a basic two point sling, is there an HK hook setup that will work as is with the rifle, or do they all require some sort of adapter?  And how do slings not snap the rear loop on the receiver?

Thanks in advance!

HK did not work for me. It kept shaving the plastic off on the rear loop.  I ended up with the blue force gear wire loops.

This ^^^ , you might do better with mash hooks if you can find them thin enough "width wise" like Troy. or just pickup some ITW's and you might need to dremel them a little thinner "might work as is" haven't tried.

What are mash hooks, what Troy stuff are you talking about, and what is ITW?

http://milspecmonkey.com/store/hardware-diy/130-itw-mash-hook-125inch-slot.html

Mash hooks pinch together to release kind of like a quick connect key ring that you pinch together rather than running the key around  360 degrees to install.

Is this something to which one attaches a different sling, or are there slings that this comes on?  And is this basically the only option that doesn't cost $50+?

They are hooks made to attach your own sling, I'm unaware of a combo yet that comes with them except a cheap combo on amazon.. Also the mash hooks are fairly cheap anyway so buy your favorite sling and use the mash hooks on it. This would work with any 1.25" sling

the MASH hooks are anywhere from $3 to $9 each depending of course on the brand.

ITW are $3 each, and made in USA http://milspecmonkey.com/store/hardware-diy/130-itw-mash-hook-125inch-slot.html ,

or if you want to buy a more premium name brand, like troy you get exactly the same thing except it's made/finished slightly better for $9 each "on sale for $6 each at primary arms" http://www.primaryarms.com/troy-mash-hook-smou-msh-oobt-00

you just need to buy your own 1.25 inch sling which is where the big cost factor comes in, anywhere from a $10 cheap chinese sling up to a really nice american made heavy duty sling such as the $50 VCAS by blue force gear. Buy a sling, thread it onto your chosen connectors MASH , HK , QD whichever you choose and attach to gun.

I use crosstac hk hooks and vcas on mine without any extra adapters. Works fine.

Get some good HK hooks, or mash hooks, and buy a sling from boonie packer. Black only, and the original adjustable 2 point/1 point sling. You will have what the vickers sling copied for half the price.

Which original 2/1 point sling?  The ones I've seen that are original to the EVO are complicated, have no instructions, and are somewhat pricy, if I remember right.

The sling is meant for any gun you want. They were the ones who started selling adjustable slings. Sorry for the confusion.

Good advice