Amplifier selection for 18” subwoofer project

I am building a Marty’s based subwoofer using an Ultimax 18” subwoofer.

I need some help/opinion on what amp to pair it with.

Currently looking at (used)
Behringer NX3000d
Crown XTi 2000
Crown XLs 2000

I hear that the behringers have quality issues which is leading me towards the crown. Afak the XLs is class D and the XTi is class A/B. I will be using the amp bridged at 4ohms and only driving the single speaker.
The XLs has direct RCA and the XTi needs an RCA to XLR cable (not a big deal).

Anyhow. Experts. What do you think?
 
The DSP on the Behringer is much more useful than the Crown. IIRC, the latter only have crossover & delay, while the Behringer add parametric and dynamic EQ, as well as a peak limiter.

I once ran sine tones through an NU3000DSP loaded down to ~2ohm nominal (although it was below 1.5ohm in places) and could get it to shut down after a few seconds.
Fortunately, music rarely demands a few seconds of full-power sine waves.

Chris