saw this this xlink linkage guard on the beta australia facebook page. i haven't personally tested it but will buy one soon and can report back.
http://propowerinternational.com/x-link-shock-guard
i foolishly didn't keep my old linkage guard from my last beta so need to put on the RR480 with all the log hopping and rocks we are doing.
it looks at least as strong as the old promoto billet one but at US$230 posted worldwide it's a lot cheaper. it's not adjustable like the promoto billet one but it could only lower the bike, something only useful to short riders.