Well check, but in that case - do NOT worry! (I weigh 225lbs.)

I might have gone +40mm depending on the size of the cracks, but 35 will be a improvement. (What matters is the amount of air in the tube cross, which goes with the square of size - so 35 to 40 is a big increase in suspension. But 28 to 35 is a big jump too.) Play around with the pressure on them as they can be run 50-85 PSI: there will be more, suspension lower in the range, but they'll be slower there too. You have to find the sweetspot for your own needs.

Oh - and you might find shock less irritating if you use a handle bar with some sweep back to give a better wrist angle, eg Mary Bars



Changing bars shouldn't hard - as long as your cables are long enough for the new bars it's an allen key job. But Marys and similar bars do need a front loading stem - ie one where you remove a faceplate and insert the bars from the front.