I would suggest checking out these mods:
1. GeekVape Aegis Legend - This mod is touch as nails and can handle quite the beating while still having an excellent chip inside. If you want one of these, check out the new limited edition Aegis Legend.
2. GeekVape Nova - Powered by the AS Chip, the NOVA not only looks beautiful with its resin design, its also really good in terms of accuracy. This mod also has a boost circuit which makes it that much better than other mods in the market. The mod itself is quite lightweight so you may like that.
3. Vaporesso Armour Pro - Equipped with a beautiful OLED display and a sleek design, this is probably the best single cell mod I've ever used! The OMNI Board 4.0 compares with the best chipsets in the game. This mod also has 2A Charging which I found to be quite useful since this is a single cell device. You can use 18650's as well as 20700's.
4. Vaporesso Polar: A bit on the bulky side but still a fantastic mod as it has the omni board 4.0 as well as 2.5A charging.
5. Vaporesso Luxe - its beautiful 'glossy' design makes it a fingerprint magnet however, you may love the look of this mod.
6. Desire Design Rage Squonk mod - This is a dual cell regulated squonk mod designed in collaboration with OhmBoy OC. It's probably the nicest dual cell squonk mod I've used. That said, it is a bulky device.
7. As someone has pointed out, squonkers are a good option however, I would suggest regulated squonkers so that you don't have to build your coil specifically for the device (they are mech squonkers). If you don't mind the mech squonkers, there are quite a few good options.
For size, I was really impressed by the Pico Squeeze. It's such an awesome device due to its small size.