Making my own Tank??? need help

Hi, I was intersted in making my own tanks... but i have some
questions...

1.  What kind of silicon do I use?
2.  Where can I get the plastic top and bottom rims that hold the tank
together?
3.  Any suggestions on how to silicon and how to put the tank
together?  

Any help/suggestions would be greatly appreciated!!! thanks!

[EMAIL PROTECTED]