Monitor 7s produce a very strong and forward sound. On their own they are a little lean on the bass extn ,nothing too bothering but definitely will push you to add a sub in future. The speakers are detailed , dynamic and fast too. There is a bit of lack of bass when compare to the PSB image series , but again what you pay is what you get. Add the sub and set the xover more than 80 (which is THX recommendation) they sound more full bodied. AVRs like Onkyo , Yamaha will make the experience more brighter , forward and at times little too hards n boomy. So probably adding something like NAD or marantz will be more sublime sound signature. However when I tried with NAD 326bee amp , vocals were way too loud and I was completely missing details. May be need to try with 350 and above series. I would say these are highpowered bookshelfs not really a big sized floorstanding speakers.
Again a lot of things depend on source, amplification , cables and room acoustics/placement. So best is to try out and let the speakers tell you more about them.
A tiny 8inch or a 10inch sealed or front ported sub will add the additional bass that is missing. Again its personal choice.