I was recommended the bariatric ones, but i dont think that it is a necessity. As long as you're getting some in.
As for post liquid stage, again i think its up to you but having this surgery tends to leave you low in iron, B12 and calcium. I was recommended elevit for pregnancy as that has a higher iron content, with taking a B12 supplement as well, i have another condition so i didnt need to take calcium. But i would recommend if you surgeon doesnt go to your regular GP and get bloods done to see how you're going and if you're deficient in anything.
Best of luck