Need recommendation of an exhaust centre - and what brand exhaust to stay away from?

Hi,

I need to replace the middle box section on an opel... (Am in Meath area).

Have used a local centre in navan previously for another car, but ended up going back three times due to it not being fitted properly and sounding like a rally car - you should have seen the amount of gun gum slapped on!, so i wont be going back there.

Im just looking for a decent crowd who do exhausts and have the recommendation of users on here. (and am not looking for cheapest - just one that works perfectly and wont be rotten in a year) ... am willing to travel a bit if needed - Meath/louth

Also, just want to check what brand of exhaust to go for as ive been told to stay away from "walker" systems and go for something like "Bosel" (not too sure of the spelling on those!)

Thanks for any recommendations