Lots and lots of different Mfg's of snow pushers . . . most have tongs/brackets that the bucket slides into and has some up and down movement. They are chained on . . . . 
Protec, - http://protechcorp.com/
Dirtworks - http://www.qualityweldingservice.com/snowpusher.html 
HLA - http://www.hlasnow.com/   - consider their snow-wing

There are many . .. .  do a craigslist search in the upper midwest.
Google has many as do most of the northern and canadian loader / shortline equipment Mfg's