I know Onkyo manuals are available in PDF format on their website, I think the same applies to Kenwood.
Kenwood to the cheapest THX certified receiver around at the moment (the VR6070) but that may be overkill for you.
Most manufacturers who don't sell a THX version will tell you its not worth it, but the thing to remember about THX is that it is a sound quality standard not a format.
That means if your receiver passes the THX select tests then it has to be pretty good, regardless of the price.
That said I ended up with the Onkyo DS797 because it would connect svideo to composite video and the component video bandwidth was high enough for progressive scan, something that the Kenwood could not accomodate.
Good luck on the hunt