BBK headers and H pipe

Hi, I'm relatively new here, and I don't know too much about cars. I drive a 94 cobra, everything's stock except a cold air intake. I have a set of long tube BBK headers and an h-pipe that I would like to install. I was just wondering if anyone knew about how much trouble these are to install. I figure I probably can't do it myself, so I'm just wondering what to expect from getting someone else to install them, like how much time etc so I can estimate what they should charge me. Anyone with help, I appreciate it!

I am located in Tennessee, just a little north of Nashville. Also, it is a stick. Speaking of which, I've noticed that I'm having a little trouble when shifting into 4th gear, I've been told that it has to do with a bad synchronizer. Anyone have any idea whether it would be better to get a transmission rebuild or find a transmission in a junk cobra or just wait it out and eventually get a new transmission once this once messes up worse. Also anybody have any idea how much a transmission rebuild would run? It seems like the sort of thing that would be fairly expensive. Sorry for asking so many price-related questions, its just that as a newbie I find it is hard to just openly trust a mechanic's estimation of cost when I have no idea what is average. Thanks!