hmmm... not a bad idea et al.
Instead of usual plastic carry cans (which are usually of very inferior quality plastic), try to get those which are used to carry engine oil/other automobile oil. These are not generally available in market; however, you can contact your friendly neighborhood kabadi-wala

or the raddi(old news papers) wala; they can easily arrange them. It costs a little more than the usual ones, but shouldn't be more than Rs.15-20 a piece, maybe even less.
Do not put the plastic cans on the saddlebag on the exhaust side, instead keep it on the left side (sari-guard side). I carried the LPG gas cylinder on our last year's trip, no problem whatsoever.
Try not to fill them to their full capacity; even if you have to do this, refill your petrol tank regularly after short intervals to remove some load off the jerry cans. Also, carry a small funnel along, it will be very convenient.