Seeking Exhaust Advice

First time post. I have a '64 GT with a bad exhaust leak and I'd like to use the opportunity to install Hooker Super Competition fenderwell headers which have been sitting in the garage for years. My question is, should I attempt to do it myself (long, but limited mechanical expertise.) by ordering a whole system to bolt it, or is it such a challenge that a good shop would be worth the money? Also, has anyone had similar positive experiences with a shop they'd recommend in NYC or L.I. area.
Thank you!

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What part number are your Hooker Super Comps? Are they the correct ones for a 64-66 A-body?