The HR10 can still record OTA and is a very good SD recorder.The HR10-250 is no longer a HDTV DVR it only uses MPEG2 signals and HDTV is now MPEG4 on Ka band. Depending on how long it has been since the receivers were used you might need to upgrade the cards.
If your new system is a SWM system the old receivers are not compatible.
The HR10 can still record OTA and is a very good SD recorder.
The OP should not get an SWM LNB in his install, if he plans to keep the HR10 active.