I always see a lot of different variants MK1, MK2, MK3, 22/45 (or something) etc. What's the difference? I was toying with getting a low-end one ($3xx) which one to go for? Just for plinking really Is there an accuracy guarantee on said pistols? Also, are they a royal pain in the ass to take apart for general cleaning?
The Standard model evolved to the MKl (sight and barrel options, 9rd magazine) which evolved to the MKll (external slide release, receiver contoured to facilitate bolt operation, 10rd magazine). Some people disliked the grip angle so the polymer MKll 22/45 (which claimed a similarity to a 1911A1 grip frame) was introduced (proprietary 10 rd magazine) and offered along with the regular MKll. The heel magazine release being less popular than thumb actuated releases led to it's redesign in the MKlll (relocated magazine release, proprietary 10rd magazine, optic mount, chamber loaded indicator, narrowed bolt ears, integral firearm lock, and
"magazine safety"
) and (concurrently) the MKlll 22/45 (proprietary 10rd magazine). Understand that magazines from various MKs do not interchange.
The most common, by far, is the MKll and, while having been replaced by the more-politically-correct MKlll, parts and magazines for the MKll are available everywhere. My opinion? Definitely, a MKll is the one to go for.
Accuracy will be better than you. Aftermarket performance parts to enhance your practical accuracy - like trigger, sear, and related parts and ergonomic grips - are widely available for the MKll.
Fieldstripping is no big deal - once you've learned how - and if you can read and follow directions you'll wonder what the whiners are whining about. (It's because they can't read.

)
Once you've learned how, you can strip in about five seconds and re-assemble in about fifteen seconds. (Poor baby!)
Regardless of the version you choose, it is safe to say that you won't regret buying one.