Amp vs Receiver is not as cut-and-dry as you would think.
There is no "amp" made for HT purposes as far as my memory goes.
When you say "amp", you're actually referring to two pieces, a "preprocessor" which combines "processor" which essentially takes the digital signals from the sources, separates the various channels, converts them to analog, and feeds them to a "preamp", all within in the same box.
It then needs to send the separate analog signals to a separate power amplifier or, more accurately, to several amplifiers, usually on one chassis.
So, this is actually three components on at least two chassis. Four on three if you want to add a tuner into the mix to fairly compare these to a receiver.
These combinations are capable of stellar performance but tend to cost a bundle in comparison to a receiver, which combines all these plus throws in a tuner, all on one chassis. That affords a considerable savings all around.
Modern receivers combine a heckuva lot pf processing power within their boxes and is still capable of mighty fine performance.
Unless you're really ready to make a financial commitment, a receiver is a very logical choice.
You should really be comparing at least mid-range receivers to pre-processors/power amps if you want a fair comparison.
If you want to hedge your bets, you can always get a decent receiver with preamp outputs. This allows you use it as is and, at any time in the future, you can add a separate power amp if you find your current speakers put too much of a demand on your receiver's output stages but, be aware, there are some mighty fine receivers out there.
