Ugly
For a +T, you need a new downpipe/exhaust system (the stock NA exhaust is not going to be very nice with a turbo, plus the cost of the downpipe is a fair chunk of the total cost of an exhaust system anyway).
You need to cut the AMM sub-harness, put a connector on it, and make a new sub-harness to relocate the AMM to the driver's side front corner.
Fitting the turbo and manifolds is quite straightforward, but you have the issue of needing to drill an oil return in the block. You also need to make up all the hoses etc to plumb it all up. You need to modify the coolant hoses with T-pieces to get a coolant feed/return for the turbo. The oil feed you can replace the oil gallery plug with a fitting to get a good oil feed (straight off the gallery so high-priority).
You also need to add an oil cooler, this involves the sandwich plate under the filter, hoses, and a cooler mounted in front of the radiator.
You need to fit the intercooler, you want the top and bottom brackets from a 740T as these will fit right into a 240 and mount everything such that it looks very factory. However, when you do this, you will no longer have enough space for the fan shroud. You can either ditch the fan shroud and keep the mechanical fan, or switch to a puller e-fan that sits right on the back of the radiator. If you do that you also need a t-piece in the bottom radiator hose for a thermoswitch to start/stop the fan.
Injectors I would just take high-impedance red/orange injectors from an 850/V70 T5 or R, in this way you can skip the need to modify the injector harness with a ballast for the stock 740T green injectors.
It is a lot of small things. If you find someone who already has experience doing +Ts on a 240, that will be your best bet for a cost-effective conversion. If you go to a workshop who don't already know it, they will spend a bunch of time figuring stuff out. At the end of the day I think for "bespoke" work like this, the cost is whatever the workshop says it is.
You can also get hamstrung easily if you need to order parts.
