Here is a variant of the Stryker ICV of the US Armed Forces: The M1133 Medical Evacuation Vehicle. It's a specified vehicle with medical (duh) interior. It has 2 different liveries and seats 5 people (3 normal ones, 2 on the stretchers) Additionally, you can equip extra cage / slat armor around the vehicle and a remote controlled 50 .cal (don't do this if you want to follow Geneva Conventions tho!) via tuning.

Before you use this, make sure to use the CWeaponInfoBlob Limit Adjuster by alexguirre to prevent the game from crashing during loading.