In the description of the MB05 it says:
"- Well MB05 Spring Airsoft Sniper Rifle - Same as MB04 But with Adjustable Stock"
So the second one has an adjustable stock and the first doesn't. That's the only difference.
If you want to know more about the WELL G22 series, go to
www.theairsoftsniper.com/chat.html and click on the AEX .pdf file at the bottom of the page. There's an article in there (page 37) about the gas version of this rifle, but it still talks about the quality of the body and all that. It seems like a pretty good gun. I'd say performance-wise it'll be very similar to the WELL L96. I could be wrong, but I don't see there being much variation between the two (performance-wise).
So the first two are identical except for the adjustable cheek rest, and the third rifle will give you similar STOCK results, but is in the L96 variant category. It's really your call - which do you think looks the best? That's what it pretty much comes down to most of the time anyway.
And please - don't use ALL CAPS in your title. It's distracting and serves no real purpose. Thanks!