Get both then, as you can save up your g slowly and make both which wont involve any cash, since both g plans are available in shop.
Both are also meant for mid to mid long range, where sazabi has funnel. Even with red comet skill, if you melee aint good, its still better to stay afar and shoot on sazabi. My advice is, go and rent both and try it out yourself and decide which suits your play style more.