It's expensive but it's the best option, sadly. The aftermarket fuel sending units are just...bad. Bad pickup design, incorrect linear reading design.
I had a Spectra one I ran for a few years. Didn't read right since it's linear. I know there's a little computer box you can buy that switches it but that takes a lot of messing around with to maybe make it work somewhat OK. The biggest problem I had with the aftermarket sending unit was the fuel pickup design. The car would run out of gas while there's still a couple gallons in the tank. Also since the pickup tube isn't as long when going uphill with like 1/8th tank it would start sucking air. That caused me a few scares on long trips!