Never tried the Python's, but their "standard" flat MI-2 sounds like it will give you what you want. This cable is higher in capacitance though, so it would be best to check with a KNOWLEDGEABLE dealer as to if you'll need the impedance compensation networks ( Zobel ).
Never tried the Oval 12's, but i found the Oval 9's to be extremely "tizzy" sounding on top and lacking any type of low frequency authority. Friends that have tried both the 9's and the 12's have typically preferred the 12's.
I agree with your comments about the Cardas. It is smooth and non-fatiguing but can also be somewhat vague in presentation. If you are looking for a heightened sense of clarity and focus ( but also somewhat "quick and lean" on bottom end ), you can give Nordost a try. They do not come across as "bright" or "glaring", simply very sharp and detailed. Whether or not you like the lack of mid-bass is both system and personal taste dependent. Sean