I doubt any major player will want another separate IT system. They all want a fully integrated system that does everything.
If you are keeping track of the maintenance you need something that is going to print the jobplans for the individual check, taking account of all the individual requirements (mod states etc). You want to order all the spares for the check and record all the manhours expended for starters. Then if you are changing lifed components you will need a tech records add on too. The list goes on and it is why the systems such as SAP, Visair, Russell Adams etc are so expensive.
To be honest, if you you are just tracking maintenance, its fairly easy to knock something up on an Access database that will do the same sort of thing.