Interconnect cable, $150 max For headphone setup

I would try to find a good used pair of AQ Jaguar. They go with just about anything. Also, its almost identical to the cable that replaced it; Columbia.

I like VanDenHul DIY and complete products for even half price of your budget.

http://www.davescables.com/

A+ copper oval=smooooth

I'm using Analysis Plus Copper Oval Micro IC in my headphone set up. IIRC I got them for around $150 like new.

Wire World Oasis

You can do no better than Clear Day ICs, which cost about $150. Moreover, you can try them for an extended period and return them free of charge if you don't like them. They surpass most of the brand name cables, including Cardas, Tara Labs, and PAD, that I have tried. You would need to spend at least $500 to beat them, in my experience. Great frequency extension, very solid bass, and really good resolution. They are sold by Audiogon member "vonwaffen", who is one of the nicest people I have met in this business. His speaker cables are very highly regarded as well and a rare bargain

I was able to pick up the Oasis for $90 new. Fits the bill and sounds good and seems solid.

I'm using Purist Audio Design Vestas. Bottom of the line from a super high end company. I've used their more expensive cables and I haven't been disappointed with the Vesta in my new smaller space.