At 25', you get improvement in many of the Austin signals. A attic mount antenna might get you by with all of Austin except CBS. KIMT is right in that zone where it might or not decode due to being in the low 20s in terms of db strength with an attic installation.
If mounted outdoors an Antennacraft HBU33 orientated to magnetic 205 ought to yield you all of Austin's affiliates you seek. You may have an outside shot also at PBS, KYIN from Iowa at this heading as well.
A eave mount would work well:
As would a chimney mount:
The reason I'm steering you so heavily away from an attic installation is that they often only work well in areas with strong signal access. You have to have strong signal access to overcome the solid object you are asking the signal to penetrate (your roof). Many people even in situations with strong signal access often have problems still. This is due to multi-path, household interference or whatnot. In short, it can be a headache which can be avoided with an outdoor installation. Antennas tend to do best when they have the best access to the signals you want.
That said, with one antenna and single run of coax to the HD homerun, I can see with the HBU33, you having reliable reception of all Austin affiliates.
Cheers.
