What product to use if ISA / TMG is not an option?

I have a need for TMG and would like to know what everyone else is doing given that TMG replaced ISA and TMG is no longer available for purchase.

I need to publish ActiveSync and use certificate based authentication.

According to this white paper http://www.microsoft.com/en-gb/download/details.aspx?id=302 the table on page 4 shows that only TMG can "Provide certificate-based authentication for Exchange ActiveSync" which means UAG is also not an option.

Is my understanding therefore correct that at this point in time Microsoft do not have anything available for this scenario?

Is there any third party products available? What is everyone else doing?

Thanks for any help
Paul