IMHO...
Save RANT for your IMC - it's way too much for the PPL. To be honest it's over the top for the IMC as well, but if it saves me an hour in the air it has paid for iteself.
As for the others, I've got the Oxford RT CDs (agree completely with Keygrip) and the Maycom. It's an occasionally-useful toy (good for listening to ATIS while you have a cup of tea) but I wouldn't say it is much use for anything else.