I'm no expert so take this cheap advice as you will.
If you want a mobile 25/50/100 watt radio with full featured headset/PTT/VOX/bluetooth, etc. you need to pony up and go Rugged. They have an extra plug wired into the rear of the radio that adapts to all their accessories. Rugged makes it plug and play, but you pay for it. I have yet to figure out how to adapt a headset to my 25W Baofeng mobile radio.
Most of the Baofeng/Chinese 5w/8w handhelds have ports (Kenwood Style) where you can connect universal headsets/PTT buttons etc. and is fairly easy to add some basic accessories. Biggest problem is these radios usually come with crap antennas so buy a quality antenna when you buy the radio.
The hard mounted radios are nice in that they haven no batteries and are always in your rig, but if you leave the rig your coms are lost (ie. spotting someone up an obstacle). This is usually the exact reason you have a radio installed and now cannot use it for the intended purpose. Handhelds are nice because they are portable and can be attached to you at all times and transferred easily to different rigs. But they have batteries that must be charged and not as much transmit power. Personally I have a unit mounted in my rig and will be buying a basic handheld for when I leave the buggy.
Try to find a radio that supports CHIRP. All these radios can be programmed manually or with alternate software, CHIRP is just the most widely used.