A lot of people now days are using Harris XG stuff for NAS, you can scan 127 talkgroups in one scan list (the most of any NAS supported brand). It's also great because you can use the same basic template in RPM for different mobiles, portables etc.
You can also use Moto or BK and I believe one other brand I don't recall at the moment. BK only supports 16 TGs for a scan list, APX supports 52, XTS is 15. Btw I'm not endorsing NAS in any way, just saying what the options are.