Unfortunately I can't see your pictures, it says file not found.
Anyway, in theory you could glue (or better, use thermal adhesive) aluminum sinks onto copper ones, but they do react together. You'd be better keeping the same elements. Also if it already has heat sinks why do you need more/new ones?
As for taking them off, you should just apply a twisting pressure to them instead of trying to pull straight off. A little solvent can work as well.
For the VRAM and VRM I used the glue that came with the AC Twin turbo 2 caled G-1.
And for the Core i used Arctic Silver 5 I think.
Yepp... I really need to do something about those wires. The graphics card with it's two 8 pin connectors hooks up to 4 of my molex contacts.
I'm looking for a powersupply with dedicated power to the grahicscard. And modular. And silent
GPUZ you say... I will google it and see if my HD4890 is supported.