Stihl ES bar if you're not on on budget, E if you are.
ES 20" 3/8 .050 - 3003 000 8822
E 20" 3/8 .050 - 3003 008 8921
Others
Sugihara bars are sweet - SV3U-0Q50HV
Cannon - CSB-S1-20-50-3
If you're on an extreme budget, I've got a new Forester 20" that I'd send you for the cost of shipping.
ES 20" 3/8 .050 - 3003 000 8822
E 20" 3/8 .050 - 3003 008 8921
Others
Sugihara bars are sweet - SV3U-0Q50HV
Cannon - CSB-S1-20-50-3
If you're on an extreme budget, I've got a new Forester 20" that I'd send you for the cost of shipping.