Hey Jack, and welcome!
Since movies are in your plan, infrequent as they may be, consider powering your speakers with an AVR. Besides offering adequate power (a 200W dedicated amp only provides 3dB more output than a 100W AVR, assuming both are fairly rated), an AVR also gives you the ability to correct the room response of your speakers, as well as providing a path to add more speakers should the need arise. Besides, not all music is 2-channel. And watt-for-watt, an AVR is generally cheaper than an integrated amp. You can save more by
buying refurb. (My Marantz is a refurb from A4L. It was indistinguishable from brand new, and it's been operating flawlessly for going on 2 1/2 years so far.)
If you want higher sensitivity to play louder without straining the speakers, maybe towers wouldn't be the worst idea, even if you do intend to use a subwoofer. Towers generally offer higher sensitivity, offering more dB per watt than a similar bookshelf. If you're married to bookshelf speakers, then the
Hsu HB-1 MK2 comes to mind as having a reasonably neutral timbre with higher than usual sensitivity.
See this review for a set of measurements. Or MTM speakers would be another option for higher sensitivity, such as the
Ascend Acoustics CMT-340 SE with
matching pedestal stands.
A ported sub will offer more output than a sealed. It's false to assume that sealed subs are more musical than ported. Both sealed and ported can be well or poorly designed, chasing the -3dB numbers game with little attention paid to the sort of control that is rarely documented by subwoofer manufacturers. If you have an aversion to vented but you still want high output, perhaps a vented
Rythmik servo sub would put your mind at ease. Not that a servo sub is required for tight response from a vented sub, but it might help to ease your tainted perceptions; and Rythmik subs do offer very good performance for their price.
What is your budget for amp / receiver + speakers + sub? If you have a particular room in mind for this stuff to live, can you tell us its cubic footage, as well as your intended distance from seats to main speakers?