What speedo do you have now? Part number would help, otherwise photo and tell us where the immo light is (bottom right in rev counter or top of mph/km/h dial)?
Swapping them is easy, takes me only a few minutes. You can change just front screen but get the same make (i.e. Bosch/Motometer or VDO), it is also quite tricky to do. Easy to crack them when you remove.