help purchasing sandbag for clients

[EdgarAllanPoe]

http://www.muscledriverusa.com/Sandbags_c_352.html

Local supply place is running a special for black Friday. They have a standard and xl sandbag....

Then I beleieve each can hold either 3 slam balls or 3 sand filler bags of 45, 18, or 8lbs. Not sure which bag to get and how much weight to get.

For example, if I got a 45 and 2 18's and only wanted to use 1 18lb filler for a weaker client would that make the bag not work as efficiently....also do these work better with sand or slam balls?

The sand would def be cheaper but prob less durable.

Most of my clients are gen pop but id also like to train with the bag using heavy weight. Only used it a few times so not sure my best option

[SFT]

I'm not sure regarding that bag. I just get rucksacks from army surplus stores. They are cheaper ($20), but probably not as nice. In any case, I have heard recommendations to fill with rubber mulch over sand. Seems that it would be easier to clean in the case of a break, and harder for it to escape from small openings over time.