In production, and available for immediate delivery...
Note that the Merkava 4 or a Russian T-90 with remote 12,7mm weapons station can be obtained for around 3 million each, just about the price General Dynamics gets for each Stryker.
Merkava 4 is just now coming into production [First deliveries to an Israeli tank battalion last month, with operational issue and training courses to new Israeli tank crews later this year.] It looks like between 50-70 will be built per year, for a total of around 400, depending on how many of the Mark 4's features [120mm gun, 5 speed automatic transmission, 1500 HP powerpack] can be retrofitted to the earlier versions, or how many of the earlier ones can be sold to foreign customers for the price of a new Mk 4.
I imagine you could get a dusty 'ol Merkava Mk. III for LESS than a Stryker! (quantity discount!) And I have no doubt that the Russians would certainly cut us a nice deal on T-90's. Personally, I'd prefer the Merkava to the T-90, but either one is FAR BETTER Stryker.
My knowledge of armor and tactics comes from reading books and playing wargames, I don't have any real "hands-on" experience. Yet it's amazing how often you can win any given simulation as long as your tanks have thicker armor and bigger guns than the other guy. Whether it's T-34's blowing away Panzer III's, or Tigers destroying T-34's, or M1A2's plinking away Iraqi T-72's, the better gun and thicker armor win every time.
Since wargamers are only playing games, not fighting real wars, a common tactic is to send in your APC's first as cannon fodder, hoping your opponent wastes his ammunition and his turns blowing away APC's while your own tanks watch & learn. It also exposes the firing positions of his tanks, APC's, and crew-served weapons.