Go to the custom installers forum and read everything IR & cabinet related.
Sounds like your doors are already in place. Is there any open shelving in your wall unit? That would be a good place to "stealth-in" your IR receiver should you choose to go IR.
Anthony pretty much covered the differences in the two strategies.
To add to Anthony's words, you can only totally hide your RF system if your remote is RF capable. If not, you will need to have a base that "sees" and relays your commands from your IR remote and you end up with an "R2D2" like 'droid sitting somewhat line-of-sight in your room. Some of these manufacturers seem convinced we'd all love to have a "Powermid" type device cluttering up our living space. I'm sure defenders would say otherwise, but I haven't seen one of these that even attempts to fit in with anyone's decor. (Okay, Tutankhamun and C3PO might have liked them.)
If you're satisfied to sit in one room and control the system through doors then a simple IR repeating system might serve you well. If you go with IR and find out later you want to "wander" then you'll end up adding RF anyway. (Unless you get in the mood to tackle hardwiring to remote repeater/receivers.)
If you want the freedom to roam the house and control volume/change: tracks/stations/discs, then an RF remote and RF system would be the ticket. Just check the specs on what you're buying so you don't get behind a few walls and find out it won't phone home. RF is definitely cool, and once you're in at the base level you won't have to meddle with how to extend your system later. (And if you're in the kitchen you won't have to pop around the corner and point the remote to mute the volume when you're busy talking to tele-marketers.)
If you don't want to pony up for an RF remote or you like your current IR remote, then it's IR repeating for you. (And if you're SURE you'll be happy with controlling from one area.)
[Link: iautomate.com]http://www.audioplex.com