The 35# gallon tank would be fine if you had an adequate water supply.
Drawing 8 gpm out with 5 GPM in and you will run out in 11 minutes.
Stay with your 200 gallon tank, providing you are getting 5 GPM in to your
tank, and you start with a full tank your run time would between 60 and 65
minutes, a 325# gallon tank would run around 70 minutes with 5 GPM in,
and 8 GPM out.
How long do you want to run before stopping to allow tank to fill back up?
How much room do you have for a water tank?