Welcome, JonK(something about your post has given me a warm feeling already). Just to clarify, the 987 is identical to the 2807, but is generally available at a slightly lower price. As was already mentioned, yes it would meet the needs that you've described. However, since you appear to be considering spending about $640 including tax, there may be an even better option.
The 2308, although a fine unit, wouldn't be as suitable since it doesn't have pre-outs. Although this might be considered an advantage in some cases since it lessens the temptation to blow money on a separate amplifier, if your future in-laws are going to use the Adcom, then pre-outs simplify matters.
Rather than the 987, which is one generation dated, if you can get a unit with similar power capability and which includes the latest HDMI, HD audio format capability, and latest Audyssey MultEQ XT processing improvements, and at a similar price, it should be considered instead. The Onkyo 705 meets these requirements and is similar overall to the excellent Denon 2808(988), but better deals are usually available. At the moment(deals come and go in as little as one day)the 705 offer at
J&R for about $650 with free shipping appears to be the best.
