Domestic room loop amplifiers - FAQ's

I would appreciate your advice. I have a severe hearing loss and wear a BTE digital aid. In 1997 I purchased a loop system from another company, which is installed on my TV with a SCART connection. In fact it's been excellent and transformed my enjoyment of TV. However I have noticed recently "and after a hearing check up" that I really need to upgrade this loop with one that has a bit more amplification, I now find I have to strain to catch dialog. So, can you advise me, which one of the units you currently sell would you recommend, e.g. which is the most powerful?