It has to be reasonably low. Machine Mart do one I find good, about £110 if I remember correctly. You could probably manage with those little ones, around £15 but they are smaller, maybe not so good other than to lift at the sills. You need stability and a good lift height.
I went low profile with mine just for security it still has decent lifting height and can get my NC off the ground more than adequately. Plus my view it gives me more time to make a correction to it’s positioning if going off the sill (lets not get into a lifting location debate).
I’ve only ever used a standard trolley jack. If your car is a lower than standard then you can run the wheels up on to some planks of wood to raise it a little. I did this with my Mk2 so I could get the jack under the diff or front cross member, or even the side jacking points.
Think you are better to make some wooden blocks with a shallow angle ramp up to the top, drive the car up onto two of them then use a larger high-lift (quick lift if you can afford) as Marpar mentions above, get a jack with a wider track and good stability. I have one of the aluminium 1.25t racing jacks from Machine Mart, it is OK but easy to damage the ram housing as there is no over pressure relief valve
If I were buying again I would go for one of these, but whatever you do get some good axle stands and stay safe.
The standard Halfords 2 tonne jack works fine on a UK-spec Mk1, unless it’s been lowered. Many imports are much lower and you may have issues trying to get the jack under the front crossmember.
The Mk3.5 on standard suspension is a bit lower but the jack still just slides under the front. It is necessary to lift the car slightly by hand as it goes in, and initial cranking has to be done with something other than the long supplied handle, since the crossmember is so far back on the Mk3 that there’s no room to move. I use a 10mm allen key. There is no issue at the back.
FWIW, the jacking points are the centre of the front crossmember and the differential. Take care not to put the jack on the engine undertray by mistake - some people have!
I supose it depends what you want from the jack, I have a little 2 ton that just fits under the front subframe, however if the rear is already up in the air the angle of the car then prevents even the small jack getting under. The other problem is standard 2 ton jacks don’t give much lift, with mine I can just about get a small axle stand under at max lift.
Those that use their jack more frequently than perhaps I do have reported that they can develop leaks and
lose pressure. Mine seems fine after a couple of years of home use.