Nope buying a whole 172 and selling your car whatever the condition its in is much cheaper if you want to do things right.
Engine mounts are the same for the dogbone top and gearbox mout. The 172 though also have a second gearbox mount bolting it to the subframe you don't necessarily need it car works fine without it and many people don't use them you can just as said drill the holes in your subframe so it fits if you want.
Parts you need
UCH /ecu etc plus all internal looms /dashs /clock (depend show your going about it) Also plip keys from doner car (locks arn't needed)
Radiator
Engine looms
idealy you want the front driveshafts hubs disks calipers.
Master cylinder /ABS computer (depending what spec our doing depedn if you need them)
Engine mounts
172 suspension (again depends what spec etc your doing)
172 hydrlic rack plus colume etc if you want that.
Air con both behind dahna dn under the scuttle panel (if you want them) plus condensor
Depending how you do they job also you'll need to sort the alternator etc out.