Muffler options for a 2005 2.5 premium auto

[Jabba]

Hi guys. I have recently gotten my mum's old 2005 liberty premium 2.5 auto. Yeah I know it's pretty funny, but you can't say no to a cheap car driven by an elderly lady to and from the shops lol! Anyway one of the mufflers has a loose baffle and makes a pretty loud buzzing noise and it's getting embarrassing. By he other one is on its way out too. My question is, what are the best alternatives to replacing the mufflers? I am happy to get a universal type one, but I do a lot if highway driving and droning is a bit of a worry. I have read a fair few threads about mufflers from other liberty models and replacing cats and resonators etc. I am after the cheapest option really. So is it worth the price or sound increase for "sporty" mufflers or are standard run of the mill replacements good enough. If they give a bit of performance gain then I am ok with the noise increase, but not if it doesn't. Also it's an auto... So there's that.

Thanks for dealing with my post night shift spaz out, but this site looked like a good source of knowledge.