Classic Arms
http://www.classicarms.us/ has Saiga rifles already converted to AK form factor for $499. You would be hard pressed to purchase one and convert it yourelf for that amount. I've had good experience dealing with Classic.
With the remaining cash from your 700 you can buy a full case of ammo and still have money left over for dinner.
That is a really good deal, though I wouldn't say that is converted to being a true AK. In my opinion, the Saiga AK platform is the best one on the market right now. (However-the VEPR platform does show some significant promise, but currently it seems to be a purely sporting version and I have not seen any TRUE conversions, such as with the Arsenal SGL series.)
Pros for BASIC Saiga or Saiga Convert(Including base model and pistol grip/buttstock/hi-cap mag conversions only)
*Made in Russia and imported by a company that is NOT Century. Can't remember if its RAAC or Legion-Izmash. Remember-WASR's and such are still put together by century.
*Great accuracy for an AK.
*Many different calibers-.223, .308, 5.45x39.5, 7.62x39
*All calibers PERFORM WELL in the system, unlike .223 WASRs.
*Great value. For $350+dealer fees+shipping you can have the base model, and then you can convert it and add whatever pistol grip or stock you want. Add a bullet guide and it can take standard AK magazines.
CONS:
*Not really a true AK, in the sense of it unless you also do the gas tube conversion, which I assume is hard or expensive judging by the fact that few do it. However, if you do NOT wish to do that you can still swap out the plain handguard and put on one with rails/grip/cappuccino machine etc.
*If you don't want to do work then there is....
SGL-21/31/41 Series Pros:
*So far they have 7.62 and 5.45, and now .410 gauge.
*Built from the Saiga Platform
*Professionally done, not garage made.
*A true AK-100 series clone. Gas tube modification is done and it has the AK-74/100 series muzzlebreak.
*Great bargain, best build AK on the market.
Cons:
*Some people say price...IDK. I disagree. Save for a bit of time and get it. Its performance will be unmatched.
ALSO, something to be considered is that both the Saiga and the Arsenal have a rail on the side that lets AK specific optics mounts to be slid on and off. With a good one, such as K-Var's KV-04S scope mount, you can zero your scope and take it on and off and it will remain zeroed. I like this feature-a lot.
IMO, the arsenal is the best buy out of them. Also, it is PERFECT for your budget.