Please do not buy a Cobra Exhaust, Absolutely shocking systems. Very average build quality, Poor welding, Poor quality Silencers.
I was unlucky enough to buy a car with a full Cobra System fitted on a previous car back in 2011, The System was build and fitted on the car in 2009 and had only covered about 10000 Miles when I bought the car when all the innards of the Silencer came out of the tailpipe!
I took it to Exhausts UK/Cobra Dealer in Sheffield who actually fitted/built the System originally along with the invoice but as I was not the original owners and the car had changed hands they would not honour any Warranty so I unfortunately had to purchase and Brand new Rear Silencer from them.
While I was under the car I could see the Pigeon sh*t welding on the flanges and about 3 Months after I sold the car the Downpipe cracked.
If the BCS is out of your budget the you could go for a Milltek, Even lookout for a used system? Plenty come up for sale that have only been fitted for a few Months at a reduced price.