ok Im thinking about buying this lens: Sigma 105mm 105 F2.8 f/2.8 Macro EX DG..

What I would like to know is this model suited to use with a Nikon D40x?

ie: does it have a motor for AF like the Tamron 90mm macro Di lens..

also, between the len's, which would be better for super closenes and detail..

If anyone could help, would be muchy appreciated