Merkur is for people with tough beards, so i guess a plastic one will not suit you at all. It was an easy transition for me as i used a gilllette knack from the 70s, quite mild as razors go. You will have to source this merkur from abroad as they don't sell them here. Not that i found any when looked a few years back.
canned foam is fine for DE. However prep is more important, i shave after a bath so the hair is soft, otherwise you need to put a wet towel on your face for a few minutes. Beard needs to be in contact with water for at least three minutes before its ready for a shave. Dry beard is as hard as iron wool, blunts the blade quicker and more likely to lead to irritation later.
But if you use cartridges with more than two blades then you need gels as it contains lubricants for more glide to reduce irritation. If you use a 3 blade or more cartridges then you are doing just one pass. If you do more passes it will be harder on your skin. The idea of the DE is its just one blade which with 3 or 4 passes moves the blade in different angles giving you a much closer shave with no irritation. Much closer than a barber can give you as they don't go beyond 2 passes. Fusion & mach 3 cannot compare to the closeness of a DE with the right technique. No way. This technique takes time to learn but its a worthy skill like a stick shift in a car.
And DE blades are cheap, i toss them every 5 or so shaves. Sharp blades are very important to getting a trouble free shave. Black platinums are the smoothest i've found, they have a coating over the blade which the green does not have so in theory last longer.
If you want to use creams out of a tube, then godrej is good enough. Getting a brush with animal hair isn't easy so you will have to stick to plastic bristles. Body shop did a decent brush for Rs.500 some time back. The gilette ones have too few bristles for my liking, they are workable but take more effort to get a good lather.
i picked up alum from some natural cure shop, it was an unfinished stone that cost me Rs.7. It was a rock that i sanded down. Works great and looks a lot more pure than the finished more clouded looking stones available.
After a shave use a non-alcohol shaving balm. A little after shave if you want, emphasis on little.