If you look around the web there are lots of good examples of mounting an Acog or other scope fairly high over the TWS Gen2 Rail on an AK type rifle.
If you want to mount a long scope low on an AK, an interesting and unusual option, the extra-long TWS handguard which completely replaces the rear sight base, and allows you to detach the TWS top cover and lift it off vertically. However, it was only briefly offered for sale, so I assume TWS only did one small production run and then decided not to make any more for some reason.
But if you want to mount a scope as low as possible on the TWS rail and a standard AK, you're limited to relatively short scopes. There don't seem to be all that many to pick from. I haven't seen this option discussed much, so here's a tentative list of some shorter scopes that, on paper, seem like they might work when low-mounted on the TWS rail: (In conformance with opticstalk.com rules, all links are either to the manufacturer's site for a decription, or to SWFA.)
1. $ 690, 5.7" long, 3.5" eye relief, 16 oz, IOR 3x25 QR-TS.
2. $1100, 7.3", 3.5" er, 23 oz, IOR Pitbull QR-TS 1:4x23.
3. $ 270, 8", 4.9" er, 8 oz, Leupold FX-II 2.5x20, SWFA.
4. $ 150, 8.1", 3.4" er, 11 oz, Nikon P-223 3x32, at SWFA.
5. $1520, 8.5", 3.5" eye relief, 21 oz, US Optics 1-4x22 SN-4S, dual FFP and SFP reticle.
6. $1270, 8.8", 3.5" er, 17 oz, Nightforce 1-4x24 NXS, FC-2 reticle.
7. $ 170, 9.2", 4" er, 9 oz, Weaver V3 1-3x20, at SWFA.
8. $ 900, 9.3", 4" er, 15 oz, Leupold Mark 4 MR/T 1.5-5x20 w/ Illuminated SPR reticle.
9. $ 318, 10.2", 3.2" er, 18 oz, Leatherwood CMR 1-4x24, (specs).
10. $ 436, 10.2", 3.2" er, 16.5 oz, Leatherwood CMR 1-4x24 w/ AK762 reticle, (description).
11. $ 500, 10.4", 3.3" er, 15 oz, Bushnell Elite 1.25-4x24, at SWFA, (older seemingly identical "Elite 4200" version, link now broken).
12. $ 260, 10.4", 4" er, 12 oz, Nikon Monarch African 1-4x20.
13. $ 290, 10.4", 4" er, 14 oz, Nikon M-223 1-4x20, at SWFA.
14. $ 800, 10.4", 3.75" er, 18 oz, SWFA Super Sniper 1-4x24, (discussion).
15. $1000, 10.5", 3.75" er, 23 oz, SWFA Super Sniper 1-6x24, (discussion).
Your experience or thoughts with these or other scopes, especially if low-mounted on an AK and TWS rail?
Note that the reticles are all over the place on those scopes; some have holdovers, some have illumination, some have both, some neither. This January 2012 SWFA SS 1-4x24 and ACOG vs. low power variable threads had some good discussion of different scopes and reticles. There also seem to be a lot scopes out there whose reticles are nearly invisible on 1x until you turn on the illumination. Personally, reticle illumination seems like a nice bonus, but I want a reticle that's easy to see at all magnifications even with no batteries.
From my own experimenting so far, the 9.2" Weaver 1-3x20 mounts very easily on the TWS rail as long as you leave off the TWS aperture sight. You could probably squeeze the aperture on there if you're willing to mount the scope a bit higher and/or farther forward. The 10.4" Nikon Monarch African 1-4x20 (which has a built-in 0.5" long sun shade) just barely squeezes onto the TWS rail; no way are you ever going to get the aperture sight on there with it. Contrary to some of the specs I've seen, the two scopes have exactly the same eye relief, and I prefer to mount them both with the eyepiece just at the rear of the TWS rail. The Nikon overhangs the rail's hinge point at the front, so you can only open the top cover part way. Although surprisingly annoying at first, it still opens enough to field strip the rifle. If I end up deciding to keep the Nikon mounted on the AK, I may try dremeling away some of its integral sunshade so I can get the TWS top-cover opened farther with the scope mounted.
Note that I have a long neck and tend to crawl the stock a bit, so you might want them mounted slightly farther back, say over the angled part of the AK's top cover or even to the very rear end of the top cover, rather than just at the end of the flat part. (But from pictures on the web, I am amazed at how ludicrously far back so many people seem to mount scopes on AKs; that just can't work well.)
Here on OpticsTalk, user "Grant" tried the Nikon Monarch African 1-4x20, Bushnell 1.25-4x, and Weaver 1-3x on his AKs, some on the TWS rail and some on a side mount. He said the 10.4" Bushnell Elite 4200 1.25-4x fit well on the TWS rail. If the length and eye relief numbers above are correct, the 10.2" Leatherwood CMR should fit just as well or even better.