You want seperate devices.
Combo devices generally dont have the same level of features, combo devices means if one part dies you need to replace it all, combo devices means if you want to upgrade one aspect you have to upgrade it al.
Thus overall combo device is a poor investment.
For 200down you could get away with a an 8x4 channel modem but it will be running near max so a 16x4 would be much better peformance wise. Even more so if doing something that can ACTUALLY use all 200mbps at once.
I have an ASUS RT-AC68P and it has been the best router I have ever owned, even better loading ASUS Merlin on it (very easy to do).
(FYI THE AC68P, 68R, 68W and 68U are all pretty much the same thing, the P only has slighlty faster CPU).