Should I bi-amp or bridge my amps to feed my speakers

Bi amping with keep the upper frequencies from getting clipped, and more sore if there is some active XO happening.

So I would bi-amp with an active XO, or some active XO type of filter, if been a Harrison Labs RCA job.

But bridging is probably better if you need more woofer notes.

Have you considered a subwoofer, and using some filter to scrape off the low notes so that the speaker do not need the amp to play them loudly?

If they are mono amps then you have to run one amp per speakers.

if they are stereo amps are you sure they are capable of bridging? 

i will assume they are stereo amps, i wold try one amp for the left and right woofers

and one for the mids and highs. 

clipping should not be an issue because tube amps soft clip, they just run out of steam.   

I vote for adding SS amp good for high current for the woofers; use the tubes as mono blocks for the tweets/mids

I should have mentioned the tube amps are in stereo they’re  HK citation 2’s. They have both been rebuilt. Also speakers are Virgo's the first series 4 ohm. Soix got it right!!

i have considered a small sub woofer, but haven’t made a move on it. 

In your situation you could use one amp for the woofers and one for the mid/treble or you could  use a single amp each for the L and R speaker.  I would try both ways. 

Bridging allows for greater watts at the expense of current. Not good for low impedance speakers. 

I would be concerned about the power compatibility of those amps with that speaker even using both amps. What is size of room?