2 post lifts

1st off if you don’t have the lift, don’t pour the pad. You can but you will be going backwards once you try to mount the lift.
The best pour of a pad is when you can pre install anchor j bolts that match the lifts mounting pads instead of drilling and Hilti bolts especially outside where rain will seep into the drilled holes and start to rust / rot your fasteners. I’m not sure where you live but if frost is issue the. Digging down below frost line is key to getting a pad that will not crack or lift. It’s going to be a large pad so rebar and or wire AND cutting in stress released lines to control the cracking is a must. 6” is a good depth but make sure it’s 5,000psi minimum and you have plenty of drainage under the pad. This cannot be just a 2x6 nailed together on top of top soil or you will have issues and not be happy. As for What lifts, there are plenty of companies out there. Always buy one size larger than you need. Trust me on that one. If cost is issue, then buy a well named unit. Easy parts availability is also important. They do break and wear out and nothing sucks more than not being able to replace a broken equalizer cable when a car is stuck 4ft off the ground.
When I get to my shop I’ll try to give you what lifts i have. Not named brand but proven good lifts at a reasonable price. syleng1