Best paintball gun for me ?

Ok well first off, the A5 is a great gun, but not for speedball. Second, HPA lasts just as long as CO2. If your field has tanks at each field then you'll be fine using HPA. But, if you have to use CO2, I would recommend something along the lines of the Smart Parts Vibe or Kingman/Spyder Electra. Both of these guns have no eyes but have soft bolts. They are lower end guns but shoot around 11-15 BPS which isn't bad but not great for speedball. Make sure you get your tank anti-siphoned and never use a remote line with CO2. The Vibe is basically an Ion with no eyes. These guns are pretty cheap which could allow for more upgrades or more tanks. Good Luck.