I think getting cheap with your bike would be the BEST way by far to screw up your holiday.

There are many reliable 150 -200cc machines that will run with the traffic all day, with adequate levels of performance in terms of braking and suspension. All of which, the Velocity and the Boss just won't do. If you plan to run in the city only, they are OK, for the highways they are dangerously inadequate (as is any other 100cc bike).

There are enough people who will be happy to "lend" you their bike for a price (bureaucracy hasn't gotten around to regulating lending yet). If you can arrange to buy a new bike, nothing like it - you just need to be able to sell it back to whoever you bought it from in the first place. You will definitely pay more than the rental charged by kinetic, but hey, at least you will not have to drop to 45kph up inclines and into headwinds!

Rental/sale/"borrowing are best done in the cities of Delhi and Mumbai, to some extent in Goa as well. Bikes to look at are the pulsar200/180/150, the HH Karizma/CBZ, Honda Unicorn and TVS RTR. Any of these bikes, new will be problem free. Used, avoid the Karizma (you'll get V strom parts faster than parts for this bike) and the Pulsar 200 (uncommon, compared to the other pulsars). Remember, 2 up running will degrade performance some for these as well.

Easiest availability of parts - pulsar 150.

Enfields. Lottery. You get a good one, you'll wonder why people keep trashing them. A lemon (and this is not uncommon AT ALL) and enfield mechs will be the single largest group of people you meet during your stay. If you must - go for a 350 cc Machismo/electra (high torque compared to the rest mentioned above, adequate stopping power - discs up front). Avoid the new flagship LB500 model - some units have recurrent engine issues the company is completely clueless about.