Do you have the Xbox360? If so I'm pretty sure (as in I've witnessed this done) the Xbox can act as the "media center" device for streaming files and playing CDs, but it will not do SACD (but we'll get to that).
To the rest - I wouldn't worry about jitter or anything of that sort with what you're describing; it won't matter if it's from the PC's internal disk or an external drive. Playing back the CD straight-up from the PC (or the Xbox) will be higher quality iff the rips you have are poorly made, but that's easy (and free) to correct - just re-rip the music at a reasonable quality, and if you're especially paranoid, use EAC (also free) to do it.
The remaining questions I have include:
- Tell me more about your PC.
- Tell me more about the size of your room.
- How open for shopping for used equipment are you?
Within $150 you won't get very much, you can get an SACD player, *OR* a receiver, *OR* speakers. But not all three. If you majorly cheap out on the amplifier and/or speakers you could probably do both (I'm not really "hip" as to what's current with multimedia speakers - I know ~5-10 years ago there were some seriously good performers on the market for $60-$250, but most of those companies no longer exist (I think Klipsch and Bose are the only two that are still holding on), and now we've got this "computer audiophile" jag that's pushing (relatively) more expensive speakers; I haven't really followed it). However if you go dig around at a thrift shop, garage sale, etc you might be able to score a complete receiver for under $50, and then save up your pennies for a better pair of speakers down the line.
No idea what to tell you about SACD - a lot of newer BD players (I know the ones from Yamaha, Oppo, and a few from Sony for certain) will play it, but none of them are "cheap" - it's kind of a premium feature. I'd ask how much you actually care about or need SACD; I've considered the format a few times myself, and the two factors that always turn me away:
- Inability to play it on my PC
- I've yet to find an album I actually want to own, that's on SACD
I know a few years ago Creative was promoting DVD-Audio for PC, the Audigy series cards (and I would assume the Extigy as well) include software drivers for DVD-A playback, but they're getting up there in years, and that's always a serious concern. I don't know if Creative's software will allow *ripping* of DVD-A discs though.
Basically what I'm envisioning is dumping the SACD feature (or at least shelving it for now), going after a decent (and decently working) used receiver, and then finding a pair of speakers down the road. Use the Xbox and/or PC for media streaming, the receiver to drive your headphones, and if the PC's current audio hardware is dumpy, address that (however, again, a lot of the more inexpensive multimedia hardware seems to be vanishing in lieu of majorly expensive "computer audiophile" parts).