I have a compact Giotto tripod with ballhead that similar to your tripod type. the problem is that when I put on 70-200 with 1D, the ballhead can't hold it rocky tight. so cant be used for long exposure as the camera will tilt.
so I got a like-new used manfrotto 329 RC4 three axis tilt tripod head (used price 45 dollars, 1/3 of new one). that can hold 20-30 lbs as it says.
another one is arca swiss B1 ballhead, that can hold 130 lbs :)
surf 'B&H photovideo' website. spend more time to compare different brands and types of tripods and heads.
I have four tripods (include one monopod). you dont need four, but one best fit.
