only for a fellow Tampa resident
: from what I've read, if have a 330i you're close to as far as you can go without changing NVH. NA Possibilities:
Active Autowerke tune (AA tune)
3 stage intake (330i already has)
I can only vouch for the AA tune. Worth it for 328i, not sure about value for 330i. Aftermarket intakes could be included but their value is debatable (at least on this forum).
I've found suspension mods to be more entertaining.
And other posters are right. You can learn a lot on your own simply by browsing this sub-forum.