I'm totally new to the gun scene in general, but I'm interested in the AK-47.
I'm interested mainly because it's got the reputation for being tough, reliable, and rather inexpensive as compared to other assault rifles.
It seems that I might need to step up this interest because of the threat of them disappearing with the incoming leadership.
It seems as though there are just as many variations on the AK.
Origin Country? Hungarian, Bulgarian, Chinese, Soviet...
You'll get a large variety of answers on that one.
Caliber? 5.45 X 39, 7.62 X 39
5.45x39mm is presently less expensive than 7.62x39mm, however it is easier to obtain 7.62x39mm. I have only seen AK variants in 5.45x39mm, .223/5.56mm, 7.62x39mm. I believe there are variants in .308 Winchester/7.62x51mm. Your 5.45x39mm AKs are AK-74s.
I'm wondering if there's any collection of info that's available all in one place so that I have a one stop place to compare...
Are parts interchangeable between one country's AK and another?
Typically yes. If you want to modify your AK variant to let's say replace the thumb hole stuck with a folder or collapsible, you need to have 6 USA made parts to make it 18 USC 922(r) compliant. I'm going to be doing that with my MAK-90. I'm going to replace the trigger, parts and the furniture (slang for stock, grip and forearm/handguard). If you replace parts on an AK variant, you want to use USA made parts, not different foreign parts. If you build an AK using foreign parts, you must use 5 or 6 USA made parts to be compliant under 18 USC 922(r). If you buy a canned rifle, the importer/maker should be able to tell you how many USA parts are in the rifle you're buying. I know my MAK-90 is little to no USA made parts so I need to replace 6 parts if I want to use my stock of choice with it.
Can I swap out barrels if I want to try the larger caliber?
From a practical standpoint, no. It's just as labor intensive as building a rifle from a parts kit and may require a gunsmith to remove the barrel on your premade AK to avoid damaging it. AKs are not like AR variants where you can replace the upper half with a different caliber. If caliber conversion is a high priority you should be looking at an AR. On ARs, you just change the upper receiver and the magazine. MGI makes a quick change AR-15 upper receiver where the barrel assembly easily removes from the upper. Just replace the barrel assembly and bolt carrier assembly and you have it converted to another caliber.
Who's AK has the latest advancements and which one is more rugged or dependable?
They're all going to be basically the same. They're all the same gas operated piston design. There are some minor variances in the trigger parts. I am no AK variant expert. I just have one that I purchased back in 1994 that I want to pimp out while it's still legal to do so under 18 USC 922(r). If there's time and money available I might build another one out of a parts kit while it's still legal.
What'm I gonna spend on different types?
Whatever the market dictates now.
Maybe a collector's site or something?
Go to ar15.com and look into the AK forums. Make sure if you buy an AK that it does not have the third hole in the receiver for the full auto sear or you may be in for a world of hurt from BATFE as they are considered to be machine guns.