Ive heard there are springs that will suite but the ones ive seen wont. need to keep searching i suppose. The tanks already in. big bugger too 650 litres. the one i used to use was only 250 and it was fine for 8-9 cars.
The Products used have less bearing on the results than most people realise. it really is more to do with the application. A hell of a lot of people cant tell the difference between the results of a mid range polish next to a stupidly exspensive one.
But they can tell the difference between a bad polish job compared to a good one.
The biggest differences i find between products isnt the finish, but the ease of use.