My motor traders policy is with Footman James, they were significantly cheaper than my previous insurance company for better cover. I have claimed off them for a windscreen and they paid out ok, took around a month but that was only because I used our own firm and not their designated company.
I refer our customers either to them or to hagerty, my contact at hagerty is phil dunne, he is a good guy, tell him scott from corvette kingdom referred you and he normally gives you a pretty keen price. They are very good at paying out quickly and with no hassle, avoid equity red star like the plague, terrible payers and horrible to deal with.
Aviva used to be good but did get a bit difficult when time to claim. The premium is the least important thing, it is when you need them that it counts. We don't do that much accident repair now so don't get involved with insurance companies that much anymore.
I'd go with FJ or hagerty.