Welcome to the forum!!
I'd get the MX -but I'm bias. This it Pentax Forums, not Minolta Forums.
I don't know your experience level with photographing wildlife, so I pass on my limited knowledge. I know patience, silence, and a long telephoto lens are key. So, here are a couple questions to ask yourself:
Will the wildlife be frighten away by the noise from the Maxxum 3 while is hunts for focus?
Will you be able to get close enough to your subjects to produce the photos you want with the maximum focal lengths you have (200mm)?
Here are some samples to help you decide.
A cicada, shot with a 50mm lens, from a distance of about a foot...
A blue jay, 200mm lens, distance about 65 feet...
A blue heron, shot with a 400mm lens, from about 200 feet...
Hope this helps.
Cheers,
Fred
Edit: the point I hoped to make here is you might consider keeping the K1000 and add a longer telephoto lens for it, rather than buying an MX or another 200mm lens.