Is it enought to attach the following documents with the I-134 form :
1) Statement of anniuty paid 2006 and
2) statement of anniuty paid 2005 and
3) US individual Income tax return(1040) 2006
4) US individual Income tax return(1040) 2005

Not if you are applying for an IR(CR)1 visa as your timeline would indicate

I just changed my timeline, it is for the K-3

Are you sure you want to give up on the other visa? I do realize everyone's priorities are different......

yes ,i see it is faster than CR-1 and i can't wait more and more.....

Then you've got it covered, assuming the income is sufficient.

CR-1 has no $1010 adjustment of status like the K-3, so is less expensive, and tends to take just a little longer than K-3.

my annual income is (20,400$) with 2 dependents ,is that ok with the poverity guideline??

Do mean a total household of 2 including your wife? If so, and you don't live in Alaska, then it meets the minumum. If the total household is three or you live in Alaska, it doesn't meet the minimum requirement.