I have discovered that my muffler is falling apart, so I am going to need a new one, does anyone have any recommendations as to what I should get put on, if possible could I get a louder muffler for a similar price to a stock one? Cheers

There are many choices but it also depends on if you rather a muffler that gives you proven performance or a muffler that is more for looks. Most, if not all of the proven performance mufflers ive seen people use on here i dont like the look of. Best thing to do is use the 'search button' many many threads on this :D

VRX & Lukeys are semi straight through smaller. Magnaflow does straight through and are the best sounding but can get pricey so shop around (ebay, amazon etc). Either option will net you a handy 5 to 7 kw increase in power but the difference in performance is subtle over stock.
Equivalent magnaflow staright through in size to full size stock magna is 14586 (universal ie use the hangers off your old one and weld onto new muffler) has the offset centre piping configuration and has 2.5' inlet/outlet - I have this on my car - a little louder than stock but the best sound!
Check the other threads, mufflers have been done to death so there's plenty of info.

General rule of thumb, if you want louder for a given muffler type, opt for the smaller sized version. And for the love of God, don't remove the resonators (unless you are fitting better ones) as magnas sound like tin can rice bombs without them (I know others here will disagree but that is my honest opinion)

Cheapest option is to go to a wrecker & find a Magna VRX and take the rear muffler off it.