Almost all Kawi 650 stand up pipes will fit
The B-pipe will fit, but it will not fit with a Kawasaki Manifold. You have to use a Westcoast or similar 650 manifold due to the head pipe angle.
The SJ mod and limited chambers fit
The Kawi 750 limited chamber hit the gas tank but can be made to fit
The B1 mod chamber fits like the kawi 750 limited chamber
the B1 limited chamber fits, but likely needs dented or a different fuel tank
SXR chamber fits, but will need to be dented, or another tank.
The TNT chamber fits like the 750 limited and B1 mod.
No drypipes fit.
EDIT: THE FOLLOWING INFORMATION IS WHEN USING A KAWI 750 MOTOR AND OP IS USING A Yamaha 701 ----->>> The easiest solution (edit: for a kawi 750) is a bored out westcoast 650 manifold, B-pipe head pipe, SJ mod chamber. You can use a stock X2 waterbox but I personally am a believer in a SJ waterbox and moving the exhaust outlet to the right side.
I overlooked that you are using a 701 and updated my pipe post above to highlight the combo I was suggesting was for a kawi 750 motor.
You shouldn't have any issues using a B-pipe with the SJ motor. The issue with the Kawis is the head pipe angle. It kicks it out and it hits the hull. Using the westcoast 650 manifold (because it has the thickest casting and can be ported the most) is a work around but it throws off all the chamber alignments. The SJ motor with the SJ B-pipe and proper motor mount/coupler adapters should drop right in. The limited chamber could give a bit more bottom end but the mod chamber is slightly shorter and fits easier. Blaster and TNT chambers do fit but not with the stock gas tank. You could switch to a Jazz tank if volume is not an issue for you. The biggest issue is the electronics. You might want to check with @Twinturbostang of RadDudes and see if they can make a Surf Brace with a SJ e-Box mount for you (normally they come with kawi 750 box mounts.
You should consider a SJ waterbox and moving the exhaust outlet to the right side. A stock SJ waterbox fits, I ran one (though I think I had the stock tank then, I'll have to try to check if it fits...) and a right rear outlet. The rear outlet though is a big hit to bouyancy though so it might be worth considering the B1 outlet between the battery and the motor. I have to check but I think I have molds for a B1 outlet cover if it's something you want to try. It might be worth considering the @JetManiac SJ waterbox because it is smaller and lighter. I haven't tried it but it looks like it could be good for the X2.
The spark arrester you have might not be the best idea for the X2 depending on the kind of riding you do. The SJ that came with the 44 mikuni had a stock airbox that was a great fit for the X2. Go ahead and try the arrestor you have but keep an eye out for a good deal on a 44 carb box.
And as always, assume I am an idiot who is half assing poop and check anything I say before spending money. Everything I did when I was messing with my X2 a lot was on a tight budget, so there are probably better ways that I couldn't afford to try.