Integrated amp instead of pre+power ? Good idea?

Well I'm not familiar with your speakers unfortunately, so I can't give any concrete suggestions for matches regarding integrateds(as far as power and sonic signature goes). Still, I've heard a lot of high end integrateds that have come down the pike. Infact, I've worked in a number of high end retail stores over the years, and have experience with the best. And as far as I've come across, tube, solid state, or otherwise(hybrid?...), that $5k Musical Fidelity integrated has to be the hands down best sounding piece I've ever heard period! I've forgotten the model(s) or whatever, but I'm sure you could do some research. Tubes may or may not sound better with your system, I don't know your speakers. Still, I've never heard better, and the MF was world class.
Hope this helps

Its a matter of personal preference and budget. There are a number of outstanding Integrated Amps Plinius, Jeff Rowland, ML, Musical Fidelity, BAT and the list can go on and on...therefore going with Integrated is NOT a downgrade in anyway. In fact I was blown away when I moved from an MF A3 Pre/power to the Jeff Rowland Concentra II and couldn't be happier.