@RCHeliGuy and
@Robert D make good points, but I think some clarification is needed here.
The earlier the generation of Emotiva amps, the better they were at handling low impedance. But, the latest Gen XPA amps can do well with low impedance, just not as well as amps that double down better at impedance lower than 4Ω.
The Gen 3 XPA amps all share the same architecture. The difference with the HC-1 and XPA-1 are that they both are single channel amps, and, other than the fact that the XPA-1 is in a larger case, these two amps use identical parts. If looking at the XPA-2, this will have two amp modules sharing a single power supply, same with all the models using more amp modules.
I tried a pair of HC-1 amps with my 13A speakers and the HC-1 amps did very well indeed! It was too close to call between the HC-1 and my Krell S-1500. It was only because the HC-1 was not distinctly better than my Krell that I ended up keeping the Krell connected to the 13A speakers (because I already owned it for years and the HC-1 represented a new cost), but I
am using an HC-1 for my C18 center speaker! Full disclosure, I'm now using a Krell DUO 300XD for the 13A speakers and it is definitely an improvement over the S-1500.
With all that being said, and considering your situation - budget, wanting a single amp, etc, - I think you'd be happy with the XPA-2. It's certainly worth a try! Keep in mind that some of all of this is splitting hairs with really good amps.