Alternate Ability Progressions
A 22 STR is nice, but it's only an additional +2 bonus over your starting point - well within the reach of Bull's Strength, and at high levels it's going to be swamped out by the magic increases anyway.
Another alternative is this ability progression :
Lv 4 : DEX (18)
Lv 8 : CHA (18)
both of these change your bonus from +3 to +4. For a Sorc, this grants additional bonus spells cast per day, a slightly higher DC, and a higher spell level cap (although that won't be a big issue for you).
Lv 12 : CON (17)
LV 16 : CON (18)
For a front line fighter HPs are *really* nice. OTOH, by level 16, maybe you won't care about the additional 16 HP.
LV 20 : Bump any of the 18's to 19.
Another point to consider : Int 8 is low enough to really hurt on the skill selection. If I recall correctly, barbarians get 4+Int skill points, which will limit you to 3 skill points a level. This may (or may not) be a problem. If it is, you might want to consider :
Lv 4 : INT(9)
LV 8 : INT(10)
LV 12: CHA (18)
LV 16: DEX (18)
LV 20: Bump an 18.
I switched CHA and DEX in this order because the DC/spell bump is probably going to be more important to you than the +1 AC. And since INT increases *aren't* retroactive (like Con is) the earlier you get rid of those penalties the better off you are.
Also, you might want to consider moving Expeditious Retreat earlier in your spell selection and taking Spring Attack - one of the barbarian's more unique abilities is his increased BASE move, and these would let you use that to the fullest. For that matter, I don't know where slow and powerful came from for barbarians - light to medium armor and increased move *screams* skirmisher (quick and deadly) to me.