No-one mentioned this, so I'll add it to the options:
Try 5 independant ICs (each programmed the same?) with only 1 PWM needed on each IC. Then program a master CPU to control the smaller (cheaper) PWM IC's. Or try 3 ICs with 2 PWM on each chip, etc....
Sorry for this late answer. Yes you have in close future new products with 5 PWM (10 bit ):
1 18f6520
2 18f8520
3 18f6620
4 18f8620
5 18f6720
6 18f8720
hi, i'm new in this things, and is a very late answer, but i think u can use dsp tms320lf24XX from texas i'm actually usin tms320lf2407 and it has 12 possible pwm's and adc, external memory/IO interface and I/O pins