I don't think 100 gpd is man enough for the job. If it is running at full capacity it will only produce 400 litres over a 24 hour period.
In reality, without high water pressure or a booster pump, it will be nearer to 200 litres.
There are 2 things that are worth spending as much as you can afford, and that is on a good pole and water production.
The best cheapy pole to get is a 17ft xtel pole, but will last 6-12 months only. As for water production, at least a 200gpd RO with a booster pump. Preferably 300 gpd with a booster pump.
Any less and you will be back on here in a month or 2 asking why you can't achieve what you hoped. Like fieldsy did.

Upgrade the RO unit and buy a carbon pole. It will make your life easier.