Adding height and second sub for 5.1 -> 5.2.2 to RM6800 kit

xroy
xroy Posts: 1
Hi guys, I have a Onkyo TX-SR494 feeding into a RM6800 5.1 kit. I'd like to add 2 more speakers and a sub for a height channel to get 7.2/5.2.2. for my home theater.

Any suggestions on what the best current purchase would be to upgrade. Looks like I can get a pair of RM6801 satellites from eBay for ~80 bucks, no idea on the sub; any better options?