Tradovate is an introducing broker for Dorman and charges $0.09 per side clearing which is basically the same as commission, in addition to their $2,400 flat fee a year. At 2000 sides a month, this works out to $0.19 a side. At 10K sides a month, it's $0.11 for the broker. Exchange and NFA fees are an additional $1.25/side when trading ES, for example.
As for platforms and visualization, have a look at Bookmap with a market-by-order feed like Rithmic (or dxFeed) showing more than 10 DOM levels. If you use it for order entry, Rithmic routing alone is typically $0.10 per side. Bookmap with one click trading + Rithmic would be worth it to me if I were a scalper.
For an alternative to AMP, have a look at Ironbeam. Commissions and margins aren't as openly advertised but you can get them to match other brokers if you ask.