I think I misunderstood your initial question. I didn't realize from your first post that you already had a pick-up and were using a single external pump. With that understanding, I'm with ya. I actually prefer a single external to and internal, and a single internal over an internal external setup.
In your shoes, I would select a quality pump that's not capable of providing fuel for a combo that's WAY over your goals. There's no need (of course) to install a pump capable of an excess of 2000 HP if you're only shooting for 600. As far as selection goes, I'm on the fence. I generally look at recent reviews for stuff like this since quality and durability seem to change from vendor to vendor so regularly.
Earlier you mentioned the BAP and that you're not a fan. Even if you don't use one of these units for the boost function, I can tell you that they are very nice for keeping voltage CONSTANT at the pump. It virtually eliminates spikes in power availability due to weak battery, flipping on head lamps, etc. I am a fan of the voltage conditioning that some of the better units provide.