which is the best amp to get to power jl audio 12w7 sub?

Do you already own the subs?

yes, and now i am using the PG zx600ti but needs changing

Looking at your current amp I would say it is putting out roughly 700 RMS at 3 ohms if you have the amp bridged. And you want more so you are looking at roughly 1000 RMS before you would notice much of a change. I would say the JL 1000/1 would be a good choice.

Do you have a set budget?

up 2 $600, and I was thinking of soundstream. Do you think they are quality amps? any other suggestions

Soundstream is a very capabale company. They have quite a few amps that would fill the bill for you.

Something like the Tarantula 800.2 would be a nice choice. I have no personal experience with the unit so I can't guarantee that the RMS numbers provided are accurate. On Ebay they have them for roughl $250 shipped.

As for other amps I would look at US Amps, maybe some older Alpines as well.

thank you, anyone else has more suggestions