The thing about leaks is, just because coolant isn't dripping out, doesn't mean air isn't being drawn in. Take a good look at the offending hose and clamp. Replace both if necessary. Try purging air out of the system and make sure your fans are blowing air through the rad, rather than away from it. If you have to drain and refill your coolant, use a vacuum filling device.
You asked about the CHR rad kit. Personally, I have no experience with them. They have sold thousands of rads on eBay, so they're probably OK. In their eBay ad, you'll notice the passenger side upper mounting tab is bent!