Have you listened to the DH Labs SilverSonic BL-1 interconnects?? Very nice for the money!!! You can find then for about 78.00 a pair.
I have used and really like the DH Labs BL-1 interconnects as well, but I would not characterize them as warm so they may not be what you're looking for.
I'd suggest a different tact. Don't mess with your cables until after you've upgraded to the pre/pro and new amp. If you need interconnects to hook up your system I'd try to minimize the cost since there's a good chance you're going to want to change them anyway once you upgrade the preamp/amp.
That said, I've found the JPS Labs Ultraconductor interconnects to be on the warmer/natural side, and if you can find a used pair they may be a good choice. Best of luck.