I prefer Yamaha but Denon and Marantz are just as good and you may prefer one of them instead.
Naming individual models would take forever and you basically get what you pay for in more power and features as you move up the price points. So you have to pick a point you comfortable with and look around there and then do a little research into reviews online etc.
A great site to look at to get you started is this one:
http://www.accessories4less.com/make-a-store/category/avreceiver/home-audio/receivers-amps/home-theater-receivers/1.html
They sell often reconditioned units for good discounts and they also have older models from a year or two back which can be cheaper. Always do your research to find the year a model was first released so you know where you stand. Even if you don't buy from this site at least it gives you a good range to start narrowing down options from.
If you want to add an amp you need pre-outs and they have a cool feature on this site where you can filter down based on units that have certain features like this. here is the same url filtered to pre-out capable units only:
http://www.accessories4less.com/make-a-store/category/avreceiver/home-audio/receivers-amps/home-theater-receivers/1.html?home_audio_key[]=Mulit-Channel Preout
Another important thing to decide now is what level of HDMI switching you need as every few years they come out with a new standard. Right now the units from last year and newer have HDCP 2.2 which allows the future 4k bluray video switching and HDR features. If you were considering buying a 4k TV in the future then it makes sense to get this support but it means you have to rule out models from previous years that may be cheaper. For many people 4k and HDR is overkill and you don't have to worry about it.
One final thing to note is that the amps are rated normally for 2 channels driven even though they have like 7 channels of amps. They are designed to mainly drive 2 channels at a time as music normally only uses 2 channels and surround speakers don't use a lot of power most of the time. In a movie when a bomb goes off behind the listener to make full use of the rear speakers the front speakers are not used much so the power just moves where it is needed. But they are not designed to drive 7 speakers at full load all the time. If you decide to use 2 speakers in one room and then use zone 2 powered speakers in the second room to play the same source at full volume you will be limited by the size of the powersupply as to the wattage you can drive all 4 speakers without getting quality issues.