Bi-Amping

They may not be described as bi-ampable but all the speakers that have two sets of binding posts,one set for mids/treble and another set for bass are bi-ampable. There are many many speakers with this style of binding post, most have a jumper strap connecting the two sets. If there is no strap then most people used jumper wires, very few actually bi-amp as appealing as this may seem. Do a search for the complexities involved and why most people don't do it..

. . . not sure you really want this to be your primary criteria for speaker purchase. I would not. Rather, pick the speakers that sound like and look like what you really want, and cost w/i your budget. In all likelihood they will have dual binding posts (most do) and be "biampable" (most are). You can verify this as your last "tie breaking" decision.

I suggest you also read up on biamping. Search the archives here and you will find extensive discussion. It sounds like you are considering "passive biamping" which rarely produces a benefit as you will read in the archives. "Active biamping" is a whole 'nother undertaking and since it removes the crossover, you may not need to worry about whether the speakers have dual binding posts.

You are facing the following 3 scenarios:

1. Two identical amps is ideal and can be used without electronic crossover. There are amps that will have line level output terminals (XLR or RCA) that make things easier by connecting them one to another otherwise you'll have to use Y-conector at your preamp output. Preamp might as well have more than one output set which will make it suitable for bi-amplification

2. Two different amps with different gains and output power. In this case if you just connect them to the speaker binding posts, you'll get overloaded or undefined bass depending which side the more powerful amp is connected to. For common sense sake we can assume that more powerful amp is connected to the low binding posts. The necessity of either electronic crossover or volume control is necessary. If volume control is used on larger poweramp, you simply will have a constant problem of tonal balance and instead of adjusting preamp volume control, you'll always have to adjust your bottom amp 'by ear' that will never be precise.

3. Opt out of biamping and get more powerful amp. THAT's my choice after trying out both above.

I have a friend who ran a tube amp on the high post and solid state for the low. Something didn't click so he sold both amps and purchased a more powerful and slightly more expensive solid state amp and used a very good jumper. In the end this worked out much better than the two dissimilar amps.

I agree with all the responses. But why are you starting off with 2 amps? Do you have a large room to fill or is the biamping for less noise/distortion reasons?
There is also horizontal and vertical biamping to the speakers. Please explain what you are attempting to achieve.