Modded SACD player: SACD or Redbook sound best?"


I have a modded SACD player (Sony 9000ES at Vacuum State Level 6 mod) and I only own redbook CD's. Before I run out and buy a bunch of SACD's (they are somewhat hard to find, and not cheap) what can you tell me about the sound quality? I understand that the difference between the two is rather large on an unmodded player: what about a player with a high level of mods such as this one? Do CD's and SACD's seem about equal on a machine such as this?

Any good source of affordable SACDs in the US? I see Ebay has a lot listed, and it seems that SACD's are pretty limited to quality recordings, which is fine with me.
dawgcatching
I usually buy them from amazon.com. SACD and CD are comparably priced there. It's best if you buy just a couple of SACDs and hear for yourself. If you like classical music then try RCA Living Stereo series. You'll find many of them at around $10. If you like jazz then try "World's Greatest Audiophile Vocal Recordings" from Chesky records. Decent compilation, excellent sonics.
Check out sa-cd.net as they have reviews and links for several sites for all sa-cd's currently available. For even better prices, check out mdt.co.uk as the pound is not too strong against the dollar and they run specials that change a lot but some great deals can be had with reasonable shipping. Also, Telarc SACD's are all on sale at Concord Music ($13.98 each) and if you buy four, the fifth is free so that makes them just over $10. each and you get free shipping on orders over $50. Ebay is also a decent source for cheap SACD's as is Amazon on some titles (but Amazon is more money most of the time than mdt.co.uk and Concord Music and often cduniverse as well.....

Hope this helps.
Did you know that in double blind listening testing conducted by the AES, no difference between SACD and Red Book was observed? That is not to say that multi channel SACD's don't sound different, they do. Only two channel have not. So, unless you are interested in multi channel, save your money. I have Miles/Blue in multi channel and it does sound better then the mixed red book.
Having heard the SACD on many fine systems/equipment,I'm not a believer.Many will disagree,but I find the high frequencies not-to-my liking.Technology dictates that this should be the way to go-BUT! Multi-channel may be excluded,no experience there.Still a two channel retro-technology person.