I've used active bi-amp with Martin Logan Monoliths. I'm not sure the Totems are suited for active bi-amping. They need to have direct inputs to the speakers for active bi-amping to be effective. This differs from merely having 2 sets of binding posts for top and bottom end. In many cases these binding posts still go through an independent filter for each speaker. They are designed for bi-wiring and may be used for passive bi-amping (meaning there is no active cross-over). In passive bi-amping you almost have to use the same amplifier for top and bottom end.
The first thing I would do is check with the manufacturer or dealer and find out if these speakers are recommended for active bi-amping. Then find out the recommended cross-over point and slope. If so, there are several very good active cross-overs on the market: Bryston, Threshold, and Marchand. I'm using a Bryston, but have heard the Marchand is excellent and is a great value. A new cross-over will cost from $500-$1100--but if you can find one used you will save quite a bit. The used ones are likely not to be the right cross-over point or slope, but you can buy a card for most of them (new) that will have the right cross-over and slope. If you are looking to buy a cross-over used, check the model and call the manufacturer and be sure you can get the card or whatever is needed to get the right cross-over point and slope.
The first thing I would do is check with the manufacturer or dealer and find out if these speakers are recommended for active bi-amping. Then find out the recommended cross-over point and slope. If so, there are several very good active cross-overs on the market: Bryston, Threshold, and Marchand. I'm using a Bryston, but have heard the Marchand is excellent and is a great value. A new cross-over will cost from $500-$1100--but if you can find one used you will save quite a bit. The used ones are likely not to be the right cross-over point or slope, but you can buy a card for most of them (new) that will have the right cross-over and slope. If you are looking to buy a cross-over used, check the model and call the manufacturer and be sure you can get the card or whatever is needed to get the right cross-over point and slope.