Been there. Done that. I wanted to use a dongle with my old and trusted Billion router. I went through about three or four different ones, but none of them are up to the job. They would overheat when given a large download to chew on. Training a noisy fan on it helped, but it was no solution.
Plus, most of the fleaBay and Amazon Marketplace sellers had no idea what they were selling, so shipped the versions designed to work with a Windows PC, rather than a router as advertised.
Once I switched to a "proper" router, I got much faster throughput too. To cut a long story short, I signed up for a 30-day plan that included a Huawei B535, then immediately gave my 30 day notice. Total cost to me: £79. The B535 supports band 32, has gigabit ports, and includes very
decent internal 2x2 antennae.
70/30 Three unlimited SIMO, replacing 3 km ADSL line.
Previously: BT ISDN, Nildram, Plusnet, 186k, EFH, Be*, Plusnet (again), Pulse8, Sky, Plusnet Business, TalkTalk Retail.