Forsooth, if you're going to forego subs, be aware that your Fortes rely on boundary reinforcement to achieve extension on the low end, and much more so than your typical speaker. This is by design. In the review I posted, note that they had them a couple feet from the wall, response dropped below 40, but they gave the impression of deeper extension. Had they pushed them closer to the wall, then they would have realized the 35 hz rated extension. The Fortes can pull this off, in spite of being reflex enclosures, because the woofs and passive radiators don't decouple until well down into the twenties. At frequencies above that, 30-50 hz or so, you can use proximity to the walls/corners to fine tune the bass. Even a few inches one way or the other will make a big difference. The take-away is that you'll probably end up placing them much closer to the walls than you would most other speakers.
FWIW, I've owned many Klipsch Heritage models over the years, including yours. They'll work however you choose to go, full range or high passed. Like I said in my first post, you'll have a lot of wiggle room, and likely go deaf before the speakers exhibit audible signs of distress. I typically used some sort of hpf on mine, but only for the very lows <25 hz. It may not have been necessary, just seemed prudent given the reflex loading.