i would have to say the alt. keep an eye on your voltage till you get both in. i have a 250amp alt, deka G31 and a yellowtop. running 3500w (2 saz-1500's and alpine pdx150.4) so im almost exactly what your looking at having. my voltage will touch 12v at idle and full tilt, at 2000rpm it wont drop under 13v. so, with less electrical you may see 10-11v (guessing) but getting to 10v is bad so just keep an eye on it and make sure you keep in 11v+
hope that helps.