[600MRG] Active antenna suggestions

[ejkkjh at gmail.com]

I am trying to set up a WSPR receive only and looking for suggestions on active receive antennas.  I would like to run WSPR receive for 600 meters using an active antenna.  It can be either outside or inside, but something not too big or high to be reasonably safe from lightning, I have had several strikes.  I would prefer not to build one, very busy with work, etc.  Receiver is a Softrock Ensemble II LF.
Any suggestions would be appreciated.  Thank you.  73
Emory  WM3M