Which 3 ton trolley Jack ?

Yeh SGS sell the same Chinese ones you will see on eBay etc. All fairly priced and decent enough. Specs very slightly but I'm 99% they are all from the same production line.

Are you sure you need a three tonne jack? You normally only lift about a quarter to half of the car's total weight since the other part stays on the ground or is supported by axle stands. I have a 2T Compac trolley jack that we use for tractors as well. Great bit of kit, made in Denmark, hence not cheap. There are plenty of threads on this topic on here by the way, use the search function.

ive had a Clarke one for about 15 years or so by now, looking back I would get one with quicker lift, the height isnt especially low so sometimes some thin planks are required for very low vehicles, other than that well worth the £90 odd I spent on it, I don't think the price has changed significantly since either!