Sorry I didnt know what drivers you had. So a Inuke 12000 would be an option or NU4 is the other option. So many variables in selecting a bass amp. I have been through many and I always end up spending way more money than if I would have spent the extra coin and bought the "expensive." one.
So simulate your drivers in whatever configuration and see what you need have excursion hit Xmax. Then see what amount of power you will need.
Some may be happy with RMS or -3db RMS capable amp. Lots of variables.
From what I have read I would not go with a nu12000 it seems there have been some issues another thing to consider what amperage is the amp going to need. In the case of the 12000 it requires a 30a circuit and depending on your set-up you may or may not want a 30a outlet. My set-up is in the living room I did not want to go that route. I am going to get either an IPR2 7500 or a Crest Pro lite 7.5, either of these will run at 2 ohms stereo all day long provided of course you are not maxing the amp for hours on end.( I will be using the amp to drive 2 SI HST18D1's. ) I am also on the cheap side so money is also an issue. If you call and look around the IPR2 7500 can be had for under 700 the DSP for under 800. I am sure there are better amps to be had but being on a budget kind of limits the options. What sold me on the amps I called Peavey support they stand by their product and offer a 5 yr. warranty. I also have a nu3000DSP it is currently being used to drive my 2 HT18D4's for what its worth its a great amp for the money however if you have a problem try getting in touch with somebody at Behringer. I called left messages I e-mailed it took almost a month before someone responded and by that time I figured out the issue.
I love my Crown XLS1000 for my HT sub duties, I know this isn't enough power for you but I would look into Crown as they have an outstanding 3 year warranty. I've read about mobile DJ's accidently dropping these in pools and Crown will still fix them within the warranty period. Plus I have options with this two channel amp as it runs down to 2ohm stereo and 4ohm mono with over 1000w rms. It doesn't get warm or loud that I can tell and I have it right under my TV in a cabinet and never have heard fans kick on.
Yer I have an xls2000 running a single ultimax 18 in bridge mode. I can't fault it! I have tried it off a single channel and it works ok too. It will run 4 ultimax 18's but at only 525watt per sub. The um18 can take well over 1000watt easy. It loves power!
I might even stick with the xls2000 for a while, see how it fares! Not sure what to do yet!
My suggestion Crest Pro lite 7.5 approx. 3750 x 2 into 2 ohm stereo same with IPR2 7500. If you are willing to buy from China FP10000 2500 x 4 at 2ohms of course my big concern what if there is a problem.
Another thing that might help call Peavey customer support. I am not saying to get this amp but considering what you get with a 5 year warranty a brand that has been around for a long time and it is not overly priced is making it a good decision for me.