Ryobi Spray Gun Advice

[Herrenovacation]

Hi bunnings workshop community hoping someone here can give me some decent advice. 

I have never used a spray gun, but i want to spray my back colourbond fence to match the other fence. I have a decent collection of ryobi tools so I would prefer to buy a ryobi product so which of the following would you recommend, have you used either and what are your experiences? 

Ryobi AIRWAVE Gravity Feed Spray Gun

or

Ryobi AIRWAVE Suction Feed Spray Gun

Thanks, looking forward to hearing what the brains trust think.