Here is my take on it
An amp thats mids adjust in the lower mid section (5150s for example) are generally paired with V30s, since they have a subtraction (so your mids on the amp compensate).
An amp that adjust in the high mids (most engls) sound good paired with the t75s, since the mids adjust in the area that is scooped (compensating).
An amp that is centered (framus cobra), sound good paired with greenbacks, since they have a bump in the low mids and are relatively flat from about 1k up.
Of course, a high mid amp paired with a V30 may be your thing, or vice versa. 5150s sound great through greenbacks. Most amps will sound thick, but sometimes dull with t75s, since the 2-4khz section adds the sparkle/sizzle to a signal.
So, its really a matter of taste. What I would do is, if you already have a cab
grab your amp, plug it into your cab, turn master volume down to zero
line out into a recording computer
grab some impulses of some speaker types
I have the setup to do this, so you might not be able to. The other option is
Find a guitar tone on an album/youtube video
Figure out what type of amp it is (the low mid, centered mids, high mid thing)
Find out what type of speaker they are using
Other than that, its driving to guitar stores and playing through the cabs, or playing hit or miss with online shops (this will eat up alot of money paying for shipping to and back, as well as re-stocking fees if they charge them).