Don't you have Wayne's top-dog SB3 already? The Duet won't be any better and you could buy just the Duet remote for what, $200. If you have a laptop, use that as the remote, that's what I'm doing and it works great.
Even with the Transporter you're going to need the laptop or some other kick-ass remote.
My dream project is this: I bought an SB a while back and sent it to Vinnie to get a "Lessloss" clock-link mod. The Lessloss DAC has a clock-master mode that completely overrides the transport clock, assuming the transport has this function. Some of the CEC players/transports do. Lessloss sold me their modded Rega Planet which can do this. This combination has handily bested some very nice stuff that has come through my doors in the last year.
Still on this rig, a copied black CD sounds better than the original. I presume, as do others, that the optical interface is one limitation of real-time redbook playback. One of the beauties of the Squeezebox implementation is it takes none of the clock information from the computer itself, rather it generates its own clock signal at the player itself. Limitation? The clock can't be that great and neither is the DAC. If we could take the Lessloss clock-substitution scheme along with it's killer DAC performance we might have the best of all worlds.
I would have had this done some time ago except that our friend Vinnie has been a wee bit busy this last year. Vinnie and Liudas at Lessloss agree this would be a relatively simple mod. I would have sent the box elsewhere to save *a lot of* time but I already have two of Vinnie's SBs along with their custom power supplies and I don't want to try to reinvent the wheel with someone else. Maybe now that Vinnie has all his new products on the ground he'll have time to work on this.
Like Rich, I'm not completely sold on mods generally. Substituting boutique parts in a given circuit might have significant results, or not. I certainly don't believe such swapping guarantees anything. However, in Dan's transporter he has completely rebuilt the output stage. His tube mods have a near-universal reputation for excellence and where the Transporter has been criticized it has been for leanness and lack of body - just the sort of place where a well-done tube output stage would be welcome. I've owned several pieces by Dan, both mods and original production and none of them had the classic, slow tube sound, all were nimble and dynamic.
Mike - what are you using for speakers now? I can't keep track.