SD WAN Lab

Hi Everyone

I would like to build my own SD-WAN lab in ESXI. I've had a go of Cisco's Viptella which is great but I think it's a bit too fiddly. I've had a go of Silver peak which I really like but I want able to lab this up in my own lab environment however I can't because I don't have license keys etc. Does anyone know other SDWAN providers whereby I can download the images and trial it all working in my own lab? I just don't want to waste loads of time building labs after downloading the images to find I can't advance because I don't have a licence key. Thanks