You can use one of the EPS connectors for the 4-pin. It should work just fine unless the pinout of the ATX connector is non-standard. If it says an EPS PSU would work, then you should be OK. Usually Tyan has a list of qualified PSUs for their mobos. Was the Hiper on the list for your mobo? If not, then why was it even considered? You could always call Tyan and see if the Hiper could work. While on the line with them, ask what an EPS12V offers that your Hiper doesn't - IOW what are the technical reasons that 2.2 units shouldn't be used.
The only functional differences between ATX 2.2 and EPS12V are split 12V rails (many PSUs that claim to have split rails really don't), and the -5V rail is gone. You could always check with Hiper to find out if the 12V on your unit is truly split or just a marketing fiction like so many others (including even nice ones like the Corsair by Seasonic units). Or you could send it off to Jonnyguru and let him review your unit for his site - he's only had one Hiper so far and that was before he tested for the reality of split rails...
Server PSU makers like Zippy, Delta and Etasis offer true EPS12V supplies if you find that's what you really need. I'd also suggest reframing your question and post it in the mobo section to find out if anyone has used an ATX 2.2 on their Tyan mobos...
.bh.