Best used universal transport/player for $1,000?

Denon 3910, you can get it modded as you grow. That DAC's in it are already pretty good, you may not need/want your other.

I should admit that I don't own a Denon. I paid up and bought the Onkyo DV SP1000 after auditioning the Denon, Marantz DV9500 and McCormack UDP-1. The Marantz and Onkyo tied, but the Onkyo had an IEEE-1394 interconnect, so I bought it. Used the best you will find is about $1300. Never looked at the Pioneer. They are all really good though, to be honest. Good luck.