Noob question

Hello forum,
this has been a great resource as I've moved into the world of computer audiophile setups

Here's my workflow, I know some of this is preferential , but if there are any glaring obvious mistakes, please let
me know

<8 Core Mac Pro, Vista 64 Ultimate, 16 Gigs Ram>

-CD ripped with Exact Audio Copy (saving as flac)
-Upsampling with r8brain (96, 24bit, very high quality)
-Playing with Media Monkey
-USB out with M Audio Transit (output 24bit, 88.2Khz )

I'm reading up on good DACs here on CA... there seems to be many... I'm on a budget, so I'm looking
over at Audiogon. Should I be purchasing a DAC that can support 24/96? Would a DAC that's 16/44 be 'clipping'
some extra quality?
Benchmark DAC?
or Cambridge DACMagic? (which will upsample my already upsampled music) Is this bad to do???
Valab NOS USB Re-Clock DAC Low Jitter Dual 1ppm TCXO (no upsampling on my upsampled music) better???

I'm using a Altec Lansing 2.1 setup for my amp. So I'd like to upgrade. The reviews here on the Peachtree Nova or Decco seem promising. It seems like a ready to go solution. But can I daisy chain their DAC to an above DAC? Is this a bad thing to do?
Or should I find a nice tube amp?

speakers are PSB 92dB sensitivity 4ohm speaker, so I guess the amp doesn't need to be too severe. 16-80 watt range.

Thanks in advance for the hand holding/advice!! :)
Dreko