BF20 or RF25

A short interdiction: I am a novice when it comes to milling machines. I have however built a small CNC milling machine that was primarily designed to cut displays in plastic boxes. This machine is working grate but has its limitations.

I am now looking for a robust machine that will allow me to cut Aluminium. I however do not want to be limited only to Aluminium. I may on the odd occasion need to cut Steel.

I have looked at both the BF20 and RF25 mills. The BF20 has a square column and seems like it may be easer to convert to CNC than the RF25 which has a round column. The RF25 however is a more robust machine.

The specs that I have on the BF20 says that it has a 800W motor and the RF25 has a 500W motor.

I was wondering if anyone has any advice on which machine may be better from a function point of view.

The machine will be used in my workshop and not for production purposes.

Thanks

The square column is always better. That BF20 mill looks great. If you have not seen it, here a link to one that has been CNC converted:
http://www.students.tut.fi/~kontkant/bf20.php.html