I had an almost identical situation over a year ago, and went with an Audiolab transport and Topping D50s dac. The latter was intended to be a bit of a stopgap measure, figuring I'd replace it after a few months if it wasnt up to my taste. I've now had it a year and its going nowhere.
The Audiolab made a big difference in sound over my Denon 1920 universal player, even with an original Cambridge audio dacmajic paired with it for a couple of months before the Topping purchase.
As in your case , redbook was my primary concern. The Audiolab does that brilliantly. I find the Topping to do Redbook well but has additional flexibility such as higher bandwidths and excellent Bluetooth connectivity.
The Audiolab made a big difference in sound over my Denon 1920 universal player, even with an original Cambridge audio dacmajic paired with it for a couple of months before the Topping purchase.
As in your case , redbook was my primary concern. The Audiolab does that brilliantly. I find the Topping to do Redbook well but has additional flexibility such as higher bandwidths and excellent Bluetooth connectivity.