Ahh yes exhausts. While a simple thing to do ones self theres always one bolt that is a total PITA! You already said you cant work on it yourself which must totally blow so yes take it to an exhaust garage. A local one near me charged me $40 to weld up my entire exhaust. They even used SS couplings. As far as gaskets go do you raelly need to ask on here? Any part store will have gaskets. Your driving a subaru not a ferrari enzo.