Unless it already has the optic base attached to the side of the receiver, you are best off using the iron sights. Stay away from the cover mounted units. If it is a Euro, go with the Kobra sighting system.

Sling wise...my .02 sez dump all the High-Speed-Low-drag crap, and find a Russian, or Egyptian (cotton) variety. Mag pouch look for the cotton duck model from China(4 pocket version) or a middle eastern knockoff. 5 good functioning mags and you are set.

If you are a big 'ol boy(long arms), you might want to consider taking a NATO length stock from K-Var.

Basically if it runs, a Kalashnikov is a "run what you brung" type of gun. If the hot dry place begins with an "A" then pick up a 5.45 model.

That is my .02...YMMV!

for serious work...almost any country of origin will be fine. chinese, romanian, russian, bulgarian, polish, yugoslavian, hungarian, east german...all good to go.

you should probably stay away from the pakistani and iraqi homegrown units, though.

for optics, rely only on the euro com-bloc rail and either russian or byelorussian sights. personally, iron sights are better if you can still see pretty good.

slings? again i'll echo jeepcreep's words...a simple sling is good. you can "silence" the noisy ak sling with tape wrapped around the front sling clip. tape will also quiet down the noisy selector lever.

the polymer lower handguard stays cooler than the wood models.

hot and sandy? run it as close to bone dry as possible. the ak will survive without lubrication.

magazines are hardly ever an issue. stick with ones in good shape and you should be fine. again, no lube is good. just deburr all sharp corners!

for faster mag changes, you may want to think about buying one of redstararms' speed wings. 3-gun shooters love them.

the only thing I don't care for on the Chinese is the leather can dry rot. Other than that it is also a good sling IMHO