How much differnce is 3" exhaust compared to 2 1/4?
Alot of people will have alot of different opinions on this subject I think.
Ranging from which gives more back pressure and if its good or if its bad and so on.
2 and a 1/4 will do you just fine I would say and even more so since it was free LOL.
Idealy I think for your set up I would probably go 2.5 or 3.0 but 2.5 is probably what most guys would run but 2 and a 1/4 is not going to make it run like crap and if there is any loss compared to larger exhuast it will not be a huge loss...and anything is a gain compared to no exhaust right lol???..
as for the H pipe....they do add a bit of ponys and they tune in your ride a bit....I personally dont like x-pipes as I think they give a car to much of a tuned sound almost tuner car with a rumble i guess lol...but a nice H-pipe ads depth to the tone I think....sorry for rambeling and hope something I said helped!