Where insurers insist on alarms and/or trackers they normally ask for particular features, grouped by Thatcham (or similar) categories, rather than any particular brand (unless they have a deal/promo with a particular supplier!). In my case the only stipulation in this area was that I had a GPS tracker fitted to qualify for insurance, i.e. no particular brand, other features or category requested.
On one of my other vehicles I have had a Thatcham Cat 5 (highest available - there are Cat 6 and Cat 7 but these have less features than Cat 5) fitted since new - this cost me circa £700 and I pay nearly £200 per year to keep it running. For this I get remote monitoring (if I ever start it without the special fob on me my phone will ring before I get to the end of the road to ask if its an authorised movement of the car), remote immobilisation, promise of better police response, geofence emails if moved, etc.. Above all it gives me a bit of peace of mind.
As per my post above, I wouldn't rely on anything on its own, instead look at layers of security such as immobilisers (electronic and physical), alarms, trackers and etching/marking/tagging (I use Smartwater) to make your vehicle look less attractive to a thief, slow them down if they do decide to have a go, and give you a chance of getting it back and the thief convicted if they do take it.
