If you have an ideal attic, the HBU-44 could work, but you won't know the reception conditions in the attic until you try. I like the dual antenna option best. You get to dial in the reception/aim of real CH-8 with out sacrificing performance going after the UHF signals.
I have some concern about the relative angle of WEAU, real CH-38. There is a construction permit for a translator on real CH-25, if it's on the air your choice of the 8-element panel antenna is great. I have not found anything to suggest it's on the air though. You'll want to call the station's engineering department to find out.
http://www.weau.com/station/misc/4835486.html
If real CH-25 is on the air, you've got a good plan. If it's going to be some time before the translator is brought on-line, there are other ideas to consider. Let's discuss those options once we know they are actually needed.