I would consider something else than Bell 430 if it has to be Cat A and like Shawn said Bell have already stopped the production and the 430 will become a dinosaur before this decade is out, just like 222's and 230's now, great machines in many ways but also kind of old school, and Bell is not going to spend a lot more budget into further testing or problem solving on these types.
About Augusta I have heard lot positive comments about AW support lately, they are really doing their homework, just look at the AW169 its gonna be just as successful as the 139 and will probably flying sooner than we think.
About the cabin space you mentioned: if it's going to be in VIP Executive configure 4-5 pax then the you are only wasting the lager Bell cabin into empty floor space compaired to A-109, they have very similar baggage, 109 is faster, and 430 sips down 600lbs of fuel per hr, A-109 about 350lbs