Stereo & Electronics - which amp for me?

I dunno anything about car audio. here is what I have
Alpine cda-85? din 1.5 unit
I THINK it has 4v pre outs...has front and rear
Focal components in the front
Sub box made for the convertible...holds 2 8" woofers....haven't bought the woofers yet.
I was thinking of the jl audio 500/5.....Would this be enuff power to power the focals and 2 8" subs? The rear speakers in a convertible are woofer/tweeter and are weak because they are so shallow. I may not even use them at all. I think they Focals are rated at 125rms

What brand and model are the 8 inch subs? What speakers do you have in the rear?

rear speakers are stock...because of the really shallow mounting depth, don't think there is much I can do there. Realize that in a convertible...the rears are in the sail panel area.....same place as the woofers in a t-top car. because the top goes down in that area, the room is much shallower than a t-top car. I dunno what subs yet...jl audio I guess...dunno what to get really

JL500/5 would work great. the 250 watts to the eights would work great and not over power them but I would recommend you get 8W3V2D4s. The front speakers will work fine since that amp puts out 125 watts to the front and 25 watts to the rear so you wont have to worry about it toasting your stock speakers. Just probably keep the gain pretty low on the backs. You can probably swap the speakers even if it is a shallow mounting area. I have never done a convertiable 4th gen so im not sure.

take the rear speakers out, and measure the depth, then replace them most likely you are gonna trash the stock speakers

the backs will be fine just keep the gains low, and thr crossover up a little. Also I 2nd the Jl 8w3v2's.

thanks! I will have to look at the specs for the 8w3v2's to see if they wil fit