Y Splitter for Bi-Amping?

I was reading a thread that may solve a problem for me re: bi-amping. I gather (this seems a bit like religion) that when using identical amps, vertical bi-amping is preferred. A prior thread talked about using a Y splitter to generate the two inputs needed for each of two amps off one set of pre-amp outputs. I poked around a bit, and there seems to be more religious fervor on the topic of split at amp end versus split at pre-amp end. Chesky's site recommends the former to avoid cable loading on the pre-amp outputs, for whatever that's worth.

Here's my question. Who makes a high quality Y splitter? Ideally, seems like I'd need a female RCA that has two tails of about 6" each, each terminating in a male RCA. Seems like kind of a joke to slap a Radio Shack connector on the end of a run of Kimber KCAG, however. The alternative appears to be a Y RCA plug, but that means another two sets of 6" KCAG interconnects. Yeah, I suppose I could roll my own, but its been a while since I owned a soldering iron. Any suggestions?

In the same vein, do people who vertically bi-amp--esp. with tubes--occasionally switch which channel is driving the top/bottom? Would it matter for longevity?

They are said to be good - no personal experience. Please report back.
I have some esoteric audio cables rca splitters which are now streetwires (?) - work well, sonically inoffensive.
I would check with the manufacturer of your preamp.
I'm slowing coming around to making my own. I'm thinking I'll try to replicate the build quality of the KCAG, meaning WBT plugs and bulk Kimber wire. It will look a bit funny, however, since WBT doesn't seem to make a female RCA cable terminated plug--they are all for chassis/PCB mount. I'll probably end up with a small plastic project box with an RCA female and a couple leads coming out of it.

Sugarbrie--were you suggesting calling preamp mfr to confirm it wouldn't damage the pre-amp or to find some kind of splitter? The "pre-amp" is a Theta Casablanca. Based on the premise that everything looks like a nail when you have a hammer, I'm assuming Theta would recommend buying another D/A board for a couple grand since they don't make cables...
I'd be trying to power a pair of ARC VT100 Mk IIIs off the output. If anyone's a real tech head who understands this stuff, the VT100s have an input impedance of 100K ohms and a 1.9V RMS input sensitivity. The Theta purports to have an output impedance of 36.5 ohms with a 10V RMS maximum output.