the spigot bush is the same on 2.25, 2.5 petrol and diesel, it's also the same for the 200tdi and most likely the 300tdi, it fits all the Series boxes (except the Stage1 box/engine) along with all the LT77 boxes attached to a four pot engine (the LT77 has more splines so uses a different friction plate but it's still 9.5")
as for clutches, in the Series there's three pressure plates and two friction plates, first off there's a choice of 9" or 9.5" so the obvious choice nowadays is for a 9.5" which brings us down to only one friction plate and TWO pressure plates (very few folks buy the 9" kit now)
so the next thing to know is which gearbox do you have ?? if it's a 2/2a gearbox you'll want the matching pressure plate (mine is an A.P. plate) with a triangular boss in the centre, this is for the release mechanism to press against (the release mechanism is integral with the box), the slave cylinder sits vertically next to the drivers footwell
if it's a Series 3 box then there will be NO boss in the centre, just the tines for the release bearing to press against, this release bearing sits in the actuating arm that clips into the bellhousing on it's pivot, the slave cylinder sits horizontally by the passenger footwell
now unless they've made a cockup or your engine or gearbox has been swapped for something completely out of the ordinary then they should have little to no difficulty fitting all the parts together
the only difficulty i've come across in the last five years (and i've swapped a few Series clutches in those five years) is actually getting the gearbox to wiggle into the spigot bush due to minor (i do mean minor) misalignment due to there being no "lead in" taper on the spigot, the gearbox needs to be dead on square to the back of the engine, sometimes you get it "just right" and they fall into place, not so often though you can be faffing and swearing for an hour or so until you get used to swapping clutches in them, i stick them in 4x4 and fourth gear so i can twist the output flange to assist lining the splines up
p.s.
off the shelf spigot bushes only cost a quid from memory
