To Bi or not to Bi? That is the question

Just a note: It is very important to as closely match the gain of two dissimilar amps as is possible for this method to stand a chance of working correctly.

If one stereo amp is for the highs and another for the lows--it shouldn't matter assuming their of good quality. www.sound.au.com has an article all about biamping--and its not a hoky one, but not super technical. Click on articles and its the first one.

I foresee two problems for you:

1)The volume you get from each amp may be different, so you end up with too much or too little bass.

2) An amp designer I know calls this "fools bi-amp" and believes that driving an amp full frequency range and using only part of that frequency range causes audible problems, esp. for the tweeter amp as there is a lot of energy in the bass frequency - which the tweeter amp isn't getting rid of but IS trying to produce.

Get yourself an active crossover, even a cheap one for now - you can always upgrade it later - I REALLY recommend this as a major gain.
Worst case, a good car one can sound OK for now - I have seen one powered by a spare car battery that was re-charged every couple of weeks!
Do some homework about cross-over slopes, use the same slope (1st, 2nd, 3rd or 4th order, also sometines refered to in dB per octave) and crossover point as the crossover in your speakers.
You can also get different alignments, I would reccomend Linkwitz-Reilley.
Don't worry about mixing amps, as long as you think the sound character is simmilar at the point where they will cross over.
I use VTL 100 monoblocks (tube), crossed over at 400 Hz to New Zealand made mostfet 250 watt per channel then to a 215 wpc mosfet parasound in bridge mode at 80 Hz to drive the sub.
This is using an active crossover. Nobody has ever commented on the mixture of amps and some people into live and studio sound professionally have been unaware they were listening to a multi-amp set up - when told, they were not suprised as they thought it "sounded too good for a passive cross over".

Only in "hi-fi" do people seem to insist on using one amp full range.
Not only does it make an amps life hard, passive crossovers are a nightmare. Expensive (VERY) to do well, hard to drive and they consume a lot of power that never even gets to the speaker drivers!!!

I was looking for a high quality Y connector and the options seemed to be solid Y splitters, which effectively mean you have to buy 3 interconnects for each channel plus the solid Y, or getting one built. In my quest, however, audioelectronicsupply.com said they can get a Kimber Kable Y connector with 2 6" male leads and a female RCA end for a fairly reasonable price. Because WBT doesn't make cable terminated female RCA connectors, they end up using a chassis mount RCA and heat shrink tubing. Apparently it isn't pretty, but you can get one built out of KCAG if you want.

I gather from my research at some point that there is some marginal benefit to "splitting" at the amp end rather than right out of the pre-amp.

Best of luck.

Thanks for all of the comments. I certainly have some experimentation ahead of me. I've thought about an active crossover but am trying to keep this simple as possible. In the end, however, that may be the route to go to get the best performance from the speakers. I'm still looking for suggestions for a good Y. You guys that are bi-amping now, do you have a pre with double outs or are you splitting the signal with a Y? If so, what are you using?? Sean, I'll look in to the partsexpress. Thanks everyone!