FORM 8879

We are planning to move abroad for about 5 mos./yr. ideally Nov-April, and eventually full time. We have a small business and 2 rental properties so we use a CPA -it's too complicated for me to do via Turbo Tax. As it is now we meet with her, share the spreadsheets, answer any questions and then she prepares our taxes. We go back and sign the 8879 (I think this is the correct form number) and she files. If we owe we send a paper check. So how would I sign the 8879 if we aren't in the US? Is there a way to sign online electronically or are we able to sign before leaving in Nov for the April filing date? Additionally if we owe can we just send a check generated by an online bank or is there some kind of paperwork/invoice that needs to be included in the envelope sent to the IRS? Is there something else to consider if we will do taxes from abroad?