OK now had a look at... rubbing the magic lantern to get the spirit of the get_iplayer back again.
I don't think presets are supported in the web based front end to get_iplayer. I set up via the get iplayer pearl box the command
get_iplayer --add-prefs --whitespace --command="copy \""<filename>"\" \""<dir>\<fileprefix>.mp3"\""
which produces a copy of the m4a file with the MP3 extension keeping both copies which is handy if you are using another media player that can't be fooled that an MP3 file contains an m4a file... then one can delete latter the unwanted files. Note as dinky told me you can use MOVE instead of COPY if you don't want this flexibility.
The statement below shows the current settings
get_iplayer --prefs-show
& the statement below clears all settings
get_iplayer --prefs-clear
The old one I was using which creates MP3 is
get_iplayer --add-prefs --aactomp3 --mp3vbr 1 --whitespace
The advantage of retaining AAC for the national channels is that you get BBC R3 in HD audio which plays through the Humax.
http://www.bbc.co.uk/blogs/bbcinternet/2010/10/hd_sound_for_radio_3.html
320k AAC R3 only (you won't get this through the Freeview channels as recordings but you will via the Humax iPlayer portal)
As far as regional and local stations in MP3 these just trip through if one is using the Windows front end through the command that dinkypinky gave me so no problem here although better if prefixes were supported in the web interface for get_iplayer. The advantage of get_iplayer is access to regional and local programming which isn't in the Humax BBC iplayer plus the ability to set up "series record". As long as the PC or device comes on once a week it will do the download.