Nice of you to help Krumlink ^^
Back to the question. I agree with these folks, its a vague question, not much info to go on. You say 'Main board', which to me, means something that gives the microcontroller (which ever one you use) power, a crystal osc, reset, and access to all I/O pins. So you can just give it power and away you go. Also, don't forget programming header.
From
Google
http://www.rentron.com/PicBasic/products/PROTO-BOARDS.htm
Very basic, and handy for one off 'simple' stuff. Alternatively, get some stripboard (veroboard) off ebay, and knock up a circuit yourself. All you would need is a regulator, a few caps, a resistor, and a crystal.
IF however, you mean 'main board' as in 'board that has everything on it and can control the world' then I think we will need more information.
Google
Considering almost ALL the 18-pin PIC's have the same pinout, don't search
Google for '16F84 board', search '18-pin PIC board'. You'll find plenty of results. Try Ebay too, I haven't plugged it enough recently.
Blueteeth
Google
ps. Subliminal messaging DOES work.