Well, 2ch gear is generally just termed that or 2.0 (there is no source of music in the format 2.1). Some 2ch units have bass management so you can integrate a sub for 2.1 speaker setup, tho (and some merely have an unfiltered sub out and no high pass for the speakers or delay management so varies as to how useful). A 2ch unit may be quite powerful, or not, depends on the unit. The advantage an avr may have over a 2ch unit in 2ch mode is often a larger power supply, and even more power only into 2ch than many dedicated 2ch units, but, as always, depends on specifics. Depends on your goals for the speaker system in the long run....like using both pair of speakers you have and adding a sub and center for a surround system, where a 2ch receiver or integrated amp will not help out.
I wouldn't bother with vinyl unless you have an existing collection myself (and I do have an existing collection and a turntable still, but haven't bought new vinyl in over 20 years). Kind of an expensive way to go right now in any case for what I do not find to be a superior delivery in general (some records can be nice, or if you are interested in a genre not represented by digital maybe). I have a larger collection of CDs that I've ripped to flac and play as such in a variety of ways (streaming on my own network to various gear, on thumb drives also), but a universal optical disc player is nice, especially if you might add video to the system. I use both Spotify and Pandora for streaming, mostly to find/confirm music to buy or even for casual listening. There's a wide variety of streaming available now, either lossy or lossless depending how much you want to spend but generally an excellent deal (for you more than the artist, tho).
Might want to run potential purchases by us before buying....
