I purchased an AMD-65 from Centerfiresystems.com for $399. It is built on a Hungarian FEG receiver by importer Tennessee Guns International ("TGI"), a company which had the distinction of being raided by BATFE in 2009 As to the gun itself, I think the quality is generally on par with other Kalashnikov-type rifles manufactured in former Soviet republics-- meaning that it just doesn't feel as well-fitted or solid as an American or western European firearm, and the finish will leave something to be desired. It does, however, feel like it will get the job done, repeatedly.
As to customizing the rifle, there is, of course, some difficulty associated with its non-standard gas tube and non-standard rear end, which is differs from other AK variants in order to accommodate the wire side-folding stock. This "problem" can be remedied, as 7.62Man pointed out, with the Krebs adapter, although this is a pretty pricey option ($90.00) as compared to the $30 bolt-on part from AMD65tech, if you're just looking for some minimal cheek weld.
My recommendation as to the front of the rifle would be to install a UTG Pro AMD-65 Quad Rail system, available for $67 on Amazon.com. I have installed this quad rail setup on my AMD-65, and it fit well with no issues. Another option is the ACR2-SC Modular Rail Forend from Ultimak. This setup, however, is only three rails, so if you wanted to top-mount an optic, you'd have to purchase their separate M7-B optic mount for $98, bringing the total price of your rail system to just under that of the weapon itself.
With respect to grips, I've mounted a Tapco SAW-style PG ($18 on Amazon) to the ass end of my AMD-65. The screw/release button for the wire sidefolder, however, interferes with the tang on the grip, so I had to cut down the tang using a small hacksaw. I've ordered a Hogue rubber PG because I don't like the hand-feel of the Tapco's hard plastic, but I haven't yet received the Hogue, so I can't comment on its quality or fit. Up front, I mounted a UTG foregrip with slots for pressure switches for my light and laser, but once you have the rails on the weapon, you can obviously mount pretty much any foregrip you want.
For magazines, you can't go wrong with the 30rd Thermold available for $7.67 from Budsgunshop.com. I have read several reviews of the AMD-65 which complain about a significant degree of magazine wobble. The Tapco 20 rd. mag that came with the gun does wobble a good bit, but the much cheaper Thermolds lock in tightly. I have no experience with surplus eastern European metal magazines, so I can't comment there.
My final customization will be having the gun refinished with Cerakote-- as stated above, the finish feels a little iffy, so I'd like to recoat the firearm to protect against any corrosion problems. With all the tacticool accessories described above, I'm sure you've deduced that this AMD-65 is more of a toy than a utilitarian piece-- so (obviously) I'm going to have the paint done in digital urban camo
Hope this helps with your purchasing decision(s) and please feel free to PM me if you have any additional questions/comments/concerns, I'll do my best to help out a fellow appreciator of the AMD!