I will/should/must/have to/am going to consider buying that hedge trimmer.

I was at a shop for garden tools looking for a hedge trimmer.
I asked the shopkeeper which hedgeteimmer is the best and he tried to convince me to buy one.
Can I say to the shopkeeper

1 I will consider buying that hedge-trimmer.
2 I should consider buying that hedge-trimmer.
3 I must consider buying that hedge-trimmer.
4 I have to consider buying that hedge-trimmer.
5 I am going to consider buying that hedge-trimmer.

I know the meaning of these modal verbs is different but I want to know if my sentences are possible.

They are all possible.

What's wrong with "I'll think about it"?