Amp Help...

I just bought one 12" alpine type-r sub. what size amp should i buy? do you have any recomendations on brands?

I would use this one is for the dual 4ohm version
http://www.alpine-usa.com/US-en/products/product.php?model=MRP-M450

and this one is for the dual 2ohm version
http://www.alpine-usa.com/US-en/products/product.php?model=MRP-M650

I probably wouldn't put more than 450 watts into it. I'm pretty sure the 12 handles up to 500. Refer to the stickies above the audio forum to see what NOT to get, otherwise, I'll leave the brand choosing up to you. Alpine is good, as mentioned but it isn't the only one.

i would get this one:
http://www.alpine-usa.com/US-en/products/product.php?model=PDX-1.600

the type r's can take 1krms daily. they been tested by mutiple people on different audio forums.

you know what, belay my last...
after reading this on the page you posted, I'm with playstation3...

The PDX mono amplifiers can be used with virtually any subwoofer(s).
PDX amps produce the same amount of power into both 2ohm and
4ohm so they will get the most from your subwoofers in almost any
situation.

the amplifiers with features like this usually do it by actively varying the current draw...it's a good deal