Photoequipment

My photoequipments.

Pentax K20D

- Pentax 50/1.4
- Pentax 30-70/3.5-4.5
- Sigma 70-300/4,0-5,6
- Tamron 18-200/3.5-6.3
- Vivitar 28/2.5
- Metz 48 (flash)

Want: Macro-lens of some kind
And when I´ve decided what brand I´ll use, is it Pentax or not, I would like to have a Sigma 10-20mm...