HELP! Header gasket replacement

Hi,

I have a question due to my limited exhaust knowledge.

I have a 360 (w/727) that does NOT have the original exhaust. The guy that had it before me installed some nice headers. I have no idea whether they are Heddman, Hooker or otherwise... I just know that I need to replace the header gasket.

Is it possible to get a new header gasket without knowing what brand of headers are on the car?

Additionally, how difficult is it to replace the driver-side header gasket myself? It does not look like there is a lot of room to maneuver to loosen the bolts.

Lastly, do I need to put anything on the gasket??? Like sealer/glue/ etc...pardon my ignorance. :)

Thanks for the help.