Its a fairly insignificant project. The most difficult part of the entire process is deciding where to physically locate the database. Depending on your current environment and resources, this may be the actual bottleneck. The entire conversion process itself, including documentation and backups, will take less than a day. Remember to remind them that the DBA doesn't actually need to create the database tables (this would be a significant project, otherwise). The tables are created during the conversion process.
Regarding the conversion being necessary. This depends entirely upon your reporting environment. Mine operates perfectly well under cinfo.mdb (which hovers between 35 and 60MB, depending on maintenance cycles). Do you have any ability to compact your System DB or is that 110 MB already compacted? You may also be able to reduce the amount of required space by reorganizing your Info Desktop folder environment - fewer folders means less space. Do you have multiple copies of one single physical report file? Fewer objects on the desktop mean less space in the database.
Hope this helps.