I don't know about subaru specialists [it's not really a rare suspension set up, pretty much anyone could fix it with the right tools] but TGM racing are at sankey lane which is near the entrance to Fleet pond [although there was a fire there recently so not sure if they're still trading right this minute, give them a ring].

http://www.tgmsports.co.uk/

Our garage is in Fleet and the only place I'd actually recommend in Fleet itself to do repairs are Ravenscroft on Fleet road.