Yes, taller tire helps that 2nd gear go faster.
You need to measure those stock bumpstops, I simply don't recall at this moment the length of both front and back...not that I would ever do it from memory anyway, as a competitor YOU must make sure your car is legal and you must make the measurements so you are confident you pass a challenge if that comes (which only comes at national level if you blow everybody's doors off). You buy the stiffer stops, trim them as needed, per this rule:
Here's the rule:
D. A suspension bump stop is considered to be performing the function
of a spring. Therefore, the compressed length of the shock at the initial
point of contact with the bump stop may not be increased from the
standard part, although the bump stop may be shortened for the purpose
of installing non-standard shocks. Bump stops installed externally
and concentric with the shaft of a shock may be drilled out to fit a larger
diameter shock shaft. Bump stops may be substituted for the purposes
of installing non-standard shocks.
Notice you must avoid contact the bumpstop earlier in the stroke. You will need to measure your OE and Koni Sports to figure lengths and trim the bumpstop length per the rule above. Sorry, no shortcut here, I can't 'give' you the answer, reading the rules and figuring your interpretation of the rules is part of the SCCA game, welcome to the fun part!