They have the most annoying ad on the radio but Gargash Insurance are not bad. Have just got my second car brokered thru them (ultimately with RSA) and they found a good deal with protected NCB, agency repairs, GCC coverage (not just Oman) and re-registration services.
just check that you can take your UK car. I came across several issues with taking my 2000 cerb. Main one being it had to be left hand drive to be registered here and driven.