What speakers will you be using? If using efficient speakers that Denon is a great receiver. You could always add a separate amp to it later if it's not enough power for you. The UMC-1 is about to be replaced with a new model that is supposed to be much improved. However, it will probably be comparable in price with the deal you can get on the Denon. But keep in mind you'll still need a separate amplifier.
As the UMC1 does not have good EQ(if this is important to you, to me it is), I would wait for the XMC1 or choose another pre/AV. I have the Denon AVR3311 with the XPA-5. The XPA-5 made a big difference in sound. An option is the XPA-5 with a cheaper AV/pre, no need for watts just pre outs and the right codecs and stuff you want on a receiver.