I have had 2 eternal systems.
The first didn't fit too well on my 3.2 estate. One of the centre section pipes needed trimming by about an inch. The second went on fine on my m f/l 3L elite.
They sound ok - a bit throaty in a way. Not perfectly quiet, but I think you'd be struggling these days short of a custom made job.
Eternals responsiveness (notably around the issue I had with the first one) was excellent - hence I bought the second.
They don't come with any fittings unless you order them. I have found the rubber hangers can be reused. You will need 2x 2 1/8" clamps (Halfords), a tube of Holts exhaust fitting goo, and I would suggest 4 8mm stainless bolts. You can order the fitting kit with the zorst but it sounds like TB's was missing bits.
It is well covered on here that getting the front bolts out is a pig. Despite heat and much care, they often shear and need drilling out. (The same GM person that designed the b@stard bolt on the stat decided to have the bolts screw into the cat rather than into centre section otherwise this wouldn't have been a problem

)
I recommend getting hold of a cobalt drill bit and some lube - worked a treat for drilling out the sheared bolt.
