your basic film SLR (single lens reflex) is a fine and versatile camera..
the Pentax K1000 is the classic "student camera"..used by thousands of highschool and college students to learn the basics of photography..
I had one, and its an excellent, if very basic, camera.
it has auto-nothing!
but thats ok..
what you need with a camera like that is a basic lens (50mm) or a simple zoom, 35-80mm or something like that.
THEN! buy a "close up lens set"..
these are filters, (lenses really) that screw onto the front of you camera lens and allow you to focus MUCH closer than you can with the standard lens..
this basic Pentax K1000 with the standard 50mm lens:
PLUS a set of close-up lenses (might also be called close-up filters..same thing, different name)
http://i20.ebayimg.com/03/i/00/e0/bb/f6_1.JPG
will allow you to take excellent VERY close-up photos..
you dont need any special lens, dont need wide-angle or telephoto..a standard lens will do.
then its the close-up lenses/filters that allow the lens to focus so much closer..
they are kinda like magnifying glasses for your camera.
buy the camera first, and see what the filter size is for the lens (49mm, 52mm 55mm 58mm etc..thats the "filter size" of the lens) then buy the close-up lenses of the correct size to match your camera's lens..
Scot