Which mono sub amp ?
 

Which would you choose and why ?

ARC Mini 500.1
Zapco Reference 500.1
Sundown SAX-1000D
JL Slash 500/1
Digital Designs CM1


Any others I should be looking at ?

I would use "non" I would get a 2 channel amp instead that could handle the power you require, they're more versitale. But if you insist on a monoblock, the Sundown Audio looks like a good choice for the money.

which 2 channel amps can handle a 2 ohm mono load , with about 500-700watts ?

Sundown Audio because I am biased.

i would look at the sundown or DD being that they have the most power, but i don't think thats a good way to look at it.

I dont need 'the most' power.. Im only running 1 old skool 12" kicker solo.
Also, a high damping factor rating is good for running subs no ?

Sundown, I'm with Jalat on this one, I'm also bias.
I have the SAZ-1500D and a 12" Nightshade in my beater.
And I have 2 SAX-100.4's in my basement waiting to go in the Sentra.
Just saving up for a pair of SAZ-3500D's

Damping factor is low on class D amps.. Class A/B (zapco) have high Damping, which make for great SQ and control on subs ! Thats why Im undecided yet ...The Class A/B puts more alternator strain though..

sundown audio all day man! check build log they are sexy! plus i think ther is 1 in the for sale section!

you are talking about subs right? and damping factor man don't even worry about stuff like that, that is jsut a gimic kind a like pre-out voltage!

you will never hear the difference in damping but you WILL pay for it!

also some more stuff on sundown audio if you are interested

http://www.soundsolutionsaudio.com/forum/Uniform-Amp-Clamp-Test-t30180.html]Uniform Amp Clamp Test - SSA Car Audio Forum

http://www.soundsolutionsaudio.com/forum/Testing-SAZ-amps-t24776.html]Testing all the SAZ amps - SSA Car Audio Forum[/U][/U]

and the best one the saz 1000 for 275 BNIB!!!!!!!!

Sundown March Sale ! - SSA Car Audio Forum