The top clearance vs. helmet height is a big problem for a Spider. If you're not worried about track events, with the helmet height requirement, then something like a street autopower bar will clear the top. Otherwise, you need to:
1. Remove the top to clear a taller roll bar
2. Create a "folding" bar
3. Disconnect the mounting pivots do the top can be raised over a tall bar then reconnected (this is what I have done).
4. Remove the bar when you want to use the top
And, as Richard says, most race series require a roll cage instead of a roll bar. My (tall) roll bar is only used for AROC time trials.