I'd go for option 1) and see how you get on... 30t is a big difference to 25t - it'll feel like having 2 or 3 extra gears below your current 25t lowest.
Don't forget to change your chain too if you've done any significant mileage on it (i.e. more than 1500-2000km).
Also, just checking, are you using clip-in pedals and shoes?
I'd go for option 1) and see how you get on... 30t is a big difference to 25t - it'll feel like having 2 or 3 extra gears below your current 25t lowest.
Don't forget to change your chain too if you've done any significant mileage on it (i.e. more than 1500-2000km).
Also, just checking, are you using clip-in pedals and shoes?