I've never met a quant trader trading for their own account. It requires some infrastructure that would be hard to justify unless you have lots of money to invest, and you're really good at it.
It is common for successful quant traders to be partners (have equity) in their firms, which means they are "trading for their own account" to some extent.
I think what he meant by "for their own account" was something smaller and personal. Not part of a larger pool containing hundreds of millions of dollars.
Not sure what you mean by portal, but I wrote my own execution system that I run on a server located close to my broker and the exchanges.
Market data is via a consolidated feed and execution via my broker to a variety of venues. I don't run any high frequency strategies so 100ms from exchange data to execution is fine for me.
I use R for most research and strategy development.
If you're making any consistent profits these days with such a primitive setup, you probably have some pretty fantastic insights that you could be selling to a hedge fund or bank
There are many more strategies that will generate consistent returns on a few million dollars than there are that will generate the same return on a hundred million dollars.
This is a key advantage of being an individual and a problem every quant fund faces as they grow.