S19 Pro is quite good for country comparing the electricity costs since they are the most powerful miners ever made hashing 110 TH/s. There are various recent articles published after the removal of banking ban stating Mining isn't legal in India, (well our country doesn't like decentralization for sure) but having a house setup might be safer. The traders from IndiaMart seems like outright scammers as you have said but truly speaking I have never done any crypto deals outside this forum.
1. Has anyone recently done this sort of thing of purchasing mining hardware from alibaba? if so then how did it go and what was your procedure of doing it?
As TheUltraElite said, you could have probably tried trading with people from Computer Hardware rather than trusting random seller from Alibaba. Trust has been a very important factor here and many do quite huge deals over here in Hardware section and Collectibles section of the forum. I am thinking of purchasing a cheap used GPU/ASIC from someone here in future to learn a bit about how mining works on a practical scale from setting up to cooling them.
2. Do you guys think i'll be successful in this endeavour?
Based on the information given by the seller from Alibaba, I think this might end up successful unless customs doesn't play any nonsense games in the middle of shipping.
According to my calculations, with the electricity rate in my area of $0.07/kwh and miners mining around 220TH/s, i would be making an okay amount of profit if i receive these two.
You would be making a not bad profit for sure and if you are facing any good set up oriented issues, you can reach out to the
Mining section of the forum. People available there are running mini-mining farms and some have been mining since 2011.
The customs have been known to even dispose off the mining hardware that enters india or in rare occassions having the customer to ship the product back to the seller paying the visa fees and shipping costs all over again.
We know how our customs works, if they find anything fishy in the parcel there are higher possibilities they might keep them aside and rob them

I was wondering if there are ways or lesser known courier services who ship to india and would clear the packages, KingTrans apparently being one.
I have absolutely no idea on this since I have never shipped miner to India, but I am thinking about the possibilities to do something in the future. I might even proceed with my first purchase on how well you receive your order.
The seller claims that even if the package through this service takes a few more days to arrive, the people working in this service "help" you with the customs if your package gets stuck .
I have imported and exported various other items including precious metals to and from India and all my experience was that it went good with India Post/USPS or other country posts. There are quite less checking with government postal while comparing with premium shippers. I am going to try importing items using Royal Mail(UK) for the first time in a couple of days and I will try to post an update here.
What do you think would be my best shot to make all this work?
The best shot would be to go with
Mantis Escrow and DIstribution & Courier service hosted by the trustworthy
minerjones for your future dealings. MJ can take care of your shipping AFAIK and might help you in getting them safely.