Buying Savings Certificates

Hi,
I would like to put some money in Savings Certificates but after looking at the forms, it isn't clear how I can get the money there. There are three options: Cash (but I don't feel comfortable in carrying 10k in cash + don't know if it would be easily accepted in the post office), Cheque (but I don't have a cheque book and would like to avoid having to buy one only for this) and Other.
What does this 'Other' mean? Anybody has done an electronic transfer to an post to buy savings certificates? Any other suggestions?
Many thanks for your answers,
Robin

Normally cheque also means bank draft.

You don't need a cheque book to get a bank draft.

or ask An Post what they mean by "other".

I'll go with the draft, thanks!