I STRONGLY suggest you read the manual for the device you're considering purchasing. For example, from what I gather about the BDV-E2100 is that it DOES NOT NEED a receiver at all.
In fact, the BDV-E2100 looks like a "Home theatre in a box" complete with a BluRay player that has proprietary little speaker cables that are color coded and plug into the speakers which also have proprietary little cables.
You fundamentally have two choices: The BDV-E2100 by itself, or a piece-wise built completely standard setup. This means a surround receiver, like the one you suggest though a 5.2 is not better than a 5.1 because low frequency isn't something humans can put a direction on very well, standard 8 ohm speakers with standard + and - connectors (whether that's bare wire or something through banana plugs doesn't matter, you can use either). Next would be a subwoofer and a basic run of the mill BluRay player. You'd connect the player to the receiver via digital coaxial or optical cable. You'd connect the speakers via speaker wire. And you'd connect the subwoofer with a subwoofer cable (looks like a typical RCA cable).
In general, you want you speakers rated high enough to handle what the receiver can deliver. So if the receiver you end up with does 105W per channel (first, that's 100W - the 105W is marketing nonsense), you'd want speakers that are around 100-150W. More is OK, less is setting yourself up for trouble. In normal electrical circuits, like your house, if you have a 25A device you must plug it into a circuit rated for 25A or higher. Plugging it into a 15A circuit would cause it the breaker to activate ("blow a fuse"). With speakers, when you try to deliver more than they can handle (so, your 100W per channel receiver at maximum volume to a 50W speaker), you simply overdrive the speaker. This typically causes the speaker to throw beyond its limits and you just tear it, ruining it permanently. Now the thing is *if* you never turned the volume up high enough to deliver more than the speaker can handle, it would actually work just fine, but that's asking for trouble where it can be avoided simply by getting speakers that can handle whatever is thrown at it.
Also worth noting for most comfortable volumes, you're rarely ever using more than 5W or so. Since the wattage and decibels are related in an interesting way, it ends up being logarithmic so that 100W isn't twice as loud as 50W. Instead, 100W is 10dB louder than 10W, which means 100W is 20dB louder than 1W. If your system could go to 100dB maximum at 100W, then at 1W you can hit 80dB while your voice is typically around 60dB. For this reason, 100W vs 200W is a meaningless and pointless discussion. The way you'd get something louder isn't by doubling the power -- you need to increase it by orders of magnitude not powers of two -- but by getting speakers with higher sensitivity. For example, to produce the same loudness as 100W with an 85dB sensitivity speaker, you would only need 25W to do that with a 91dB sensitivity speaker. If you're looking for lower power usage, then higher sensitivity speakers is the way to achieve it. As a bonus, they'll also sound louder no matter where you put the volume knob compared to lower sensitivity speakers so you're less inclined to turn it so far up anyways, which means that a high sensitivity speaker that isn't technically rated to handle 100W could still be completely usable on a 100W receiver provided you understand that you shouldn't turn it up all the way.