I don't know a lot about arrangers. I like workstations more like the Roland XP and such.
That being said, a friend of mine wants to buy a keyboard that has a lot of drumbeats programmed into it, with the ability to edit these beats. He wants it to be portable as well. I'm guessing maybe 61 keys. Something with decent sound canvas that isn't going to sound all square and cheesy. around $800.
A Yamaha PSR2000? I really don't know these arrangers very well. He wants actual line outs instead of just a headphone jack.