On Windows 8, is there any way of running IE8 & 9 besides using rendering mode in IE10 or creating a virtual setup? As with previous versions of IE, IE10 doesn't seem to render 8 and 9 properly. Also tried IE Collection which won't install any of these versions on Windows 8.
I don't believe this is possible due to programmatic differences and dependencies Microsoft creates (for whatever reason). The typical alternatives are to install a Virtual Machine (Microsoft Virtual PC, or VirtualBox, or VmWare Desktop Products) with XP or W7 and have a Virutal Machine for each unique IE version you need.
Update
Anyone using Windows 8, Virtual PC has been renamed to the server version Hyper-V, comes with Windows 8 by default, and is not installed by default.
Update 2
I'd also recommend taking a look at https://www.browserstack.com/. It's a very nice product (I have no affiliation with that company, I've only used the product with much success).