The Kranzle K1322TS/K1122TST/K1622TS will draw from a tank independently as they have a self-priming pump. The Kranzle manual states that it can pull water from up to 1m below, but we have yet to test that.
Anything level with your tank or slightly under the machine will work perfectly. Please don't use an external pump, as this can cause issues with the Kranzle. Also, be sure to note the power requirements on the product page. You'll need at least a 4800W generator to run a Kranzle.
Kranzle K1322TS Pressure Washer
Kranzle K1622 | Kranzle Pressure Washer
Kranzle K1122TST Pressure Washer