Yes, you'll need an avr with pre-outs. They really don't have flavors like warm, chocolatey, cold, etc, at least not without some tweaking of dsp/eq. I wouldn't bother with the slimline Marantz series, tend to not have a full feature set and limited pre-outs (and amp section). I'd look at the Denons myself, tend to be better priced than Marantz (but are sister brands and share a lot, too). Pick an avr by the price/feature set/amp section that works best for you....or if you want to spend more money, you could think about a dedicated pre-pro and buy some more power amps....
ps Onkyo/Pioneer I'd be hesitant to consider due financial issues but their Dirac eq feature could be interesting....and for that matter Sound United (owers of Marantz/Denon) has announced a sale to a medical company (Masimo) and we're wondering how the future of that could work out....