Here's some stuff we do for all sports, hitting core, speed, balance, hand & wrist strength, etc. Most of it is done with normal weightroom equipment and a few cheap supplies cuz that's all we can afford. A lot of this stuff came from working with MMA people. Let me know if you find some things that help boxers.
http://www.youtube.com/watch?v=dfhfqy6QVG4
http://www.youtube.com/watch?v=IkO0vpcpT6I
http://www.youtube.com/watch?v=YTCIA5umib8
http://www.youtube.com/watch?v=p4pJrjx-xAE
http://www.youtube.com/watch?v=8uRl4h1zzys
http://www.youtube.com/watch?v=pMJxof-5UCQ
http://www.youtube.com/watch?v=gqYtT85xJeE
http://www.youtube.com/watch?v=zU6xwnMOhkc
http://www.youtube.com/watch?v=DWK5fNcx1Ns
http://www.youtube.com/watch?v=v3d3ztBHdFc
http://www.youtube.com/watch?v=1Jjrp1jZ3n4
http://www.youtube.com/watch?v=FgvCUZq05NU
http://www.youtube.com/watch?v=ONiHN6fn8Io
http://www.youtube.com/watch?v=QEhkMRjf0_w
http://www.youtube.com/watch?v=Sku5rjcmreo
http://www.youtube.com/watch?v=sDBur2JSWAA
http://www.youtube.com/watch?v=xj2Dft1bV-w
http://www.youtube.com/watch?v=dfhfqy6QVG4
http://www.youtube.com/watch?v=IkO0vpcpT6I
http://www.youtube.com/watch?v=YTCIA5umib8
http://www.youtube.com/watch?v=p4pJrjx-xAE
http://www.youtube.com/watch?v=8uRl4h1zzys
http://www.youtube.com/watch?v=pMJxof-5UCQ
http://www.youtube.com/watch?v=gqYtT85xJeE
http://www.youtube.com/watch?v=zU6xwnMOhkc
http://www.youtube.com/watch?v=DWK5fNcx1Ns
http://www.youtube.com/watch?v=v3d3ztBHdFc
http://www.youtube.com/watch?v=1Jjrp1jZ3n4
http://www.youtube.com/watch?v=FgvCUZq05NU
http://www.youtube.com/watch?v=ONiHN6fn8Io
http://www.youtube.com/watch?v=QEhkMRjf0_w
http://www.youtube.com/watch?v=Sku5rjcmreo
http://www.youtube.com/watch?v=sDBur2JSWAA
http://www.youtube.com/watch?v=xj2Dft1bV-w