Nah, every now and then you will see some people selling their old Evo DVD sets on here. You’re really not going to find these anywhere else. As for SBO DVDs, seems like Play-Asia no longer stocks SBO DVDs older than 2007 (They still stock all the 2007 DVDs) even though some of them are still available directly from the manufacturer.
You can still buy these SBO DVDs straight from Enterbrain:
SBO '03 Vol. 2
SBO '03 Vol. 3
SBO '04 Vol. 3
SBO '06 Vol. 3
The rest you might be able to spot at auction. Kinda weird that there aren’t that many on Ebay anymore. There used to be more for sale. Here is one of the few SBO '06 Vol. 1 You should try searching for ‘Tougeki’ when you look for SBO DVDs.