Hi,
AVR would be 5.1 and so this means that you will add the other speakers later? The BA XS 2.1 is more of a stereo setup.
You could perhaps use a stereo amp like Marantz or Cambridge Audio (also available on HiFi Mart) if you are looking at a pure stereo setup.
Depending on your budget, if you want to own an AVR that is both good for movies and music, would suggest to go for Marantz NR 1504 which would pair well with the BA XS 2.1 and later you can add more speakers when you have the budget....perhaps bookshelf speakers of BA and the centre.
I have been using the BA XS 5.1 with Marantz for over a year now and the experience has been awesome for music / movies etc.....
The key for you is to audition all possible AVRs which fit your budget and features requirements....if open to pre owned, check the Sale by Owner section or HiFi Ads, there are some cool AVRs being sold at a bargain by individuals which are hardly used...you may just get lucky...all the best..