Pro-ject Pre Box, Marantz integrated, or ?

With the chara post limit, it is difficult to relay my thoughts, but I will start with a description of my current system (also provides budget ideas):
Pro-ject Debut III turntable into Pro-ject tube box phone pre (also using Pro-ject Speed Box)
Marantz CD 5004 CD player through a Musical Fidelity tube buffer
Sansui AU 7700 integrated (using as a pre)
Preouts going through another Musical Fidelity tube buffer
Marantz MA6100s power amplifier
Silverline Prelude speakers
Signal Cable I/C's, power, and bi-wire speaker cables
I have grown weary of the vintage Sansui. After about 20 minutes of play, I start to get some static, even at low volume levels. While I can not be sure it is the Sansui, I am apt to lean that way. Where to next?
I can't comment on the Pro-ject Pre Box but right now, I'm listening to the Pro-ject Stereo Amp Box. It's well built and solid for such a small stereo amp; not the last word in detail but very listenable. I've used it driven directly from a Squeezebox Touch using the Touch volume control. Also, I've driven it from the outputs of a MHTD Labs Constantine DAC using the Windows7 volume control. Finally, I've connected it to the pre-outs of a PS Audio C-100 Integrated Amp. Speakers are Gallo Reference Strada's. It's a decent amp and I'll keep it for a backup. The only problem I have with it is that when it clips it clips hard. As long as I don't try to push it to hard it sounds fine.I wish it had a little more power, but for an amp that fits in the palm of your hand, you can't expect window shaking volume. My speakers aren't the most efficient which doesn't help.

You can always order the Pre Box from Amazon and give it a spin in your system. If you don't like it, then return it.

I've contemplated purchasing the Pre Box, Nuforce U-DAC2 and pairing it with the Amp Box. Sources would be the computer and a Squeezebox touch. Imagine a audio system that takes up less space than a small loaf of nut bread from the local market.
Thank you for taking the time to post a response Prpixel. Given your post and the way I was already leaning, I decided to throw in the towel and ordered the Marantz PM5004 last night.