Need some advising

I'd definitely try to small vintage tube amp. There's plenty on Ebay and Audiogon. Many Klipsch owners use those and love them.

I agree with Wireless200. Klipsch horn speakers can sound bright and overly lean with the wrong amplification, and something like the Creek would be one of my last suggestions.

Tubes would be the way to go and there are plenty of options, vintage and modern. I wouldn't go too old, though, unless you can find something like a fully restored Fisher or Scott receiver or integrated. On the modern end, you should easily be able to find an integrated tube amp from companies like PrimaLuna, Cayin, Antique Sound Labs, Eastern Electric and so on.

I've had a PrimaLuna ProLogue Two running for about three of four years now. It may be a few bucks more than what you want to spend, but it should give you many years of reliable service. It also pairs well with many speakers and is resolving enough to do justice to components many times its price, so it can remain the backbone of your system as you upgrade.

the creek is sweet with the chorus, the heresy or the forte

Any class A amp will be great.

It depends on what kind of sound you want - you can drive them with just about anything, so you have alot of choices. I would agree with the tube suggestions, they match very well with horns. I have a PrimaLuna Dialogue 2 driving my Klipsch Cornwall 2's. I would stay away from really powerful amps personally - you just don't need the power with the very efficient horns.