What radio manufactures?
What radio models?
If your looking at Motorola, I'd check out the Waris/Pro series radios, HT750/1250/1550 or CDM750/1250/1550. I'm not a real big fan of those series - but that's personal. They work great for a lot of people. You'll want to find one that has an "S" in the model number, for example:
That character that's bold will be the band that your looking for in that series.
There are models of the HT750 and HT1250 that have a 450-512 mhz frequency range. They aren't too popular with ham operators since the low end is 450 mhz. One of the guys in my squad bought a HT750 in the range you are looking for last year. You just need to find them. The bat labs site can help with the model numbers.