Yep, I completely agree with this. Unless you are competing every weekend and fighting for a top podium spot, I would just go with the best tire you can buy in either P205/40, P205/45, or P215/40. The roads in Tampa are really nice, so you don't need the extra sidewall that is needed in other parts of the country. There are also 205 tires that run wide, so look over the actual measurements of the tire. From personal experience, I ran faster lap times on the stock tires than I did with a wider Yokohama tire. The reason was the compound and not the width. My fastest lap time on a road course was in my old Focus running 205 wide BFG race tires and not in my 300+hp Mustang running P275 wide street tires. Once again, it was the compound and not the width.
For turn-in, you want the least amount of sidewall. When you turn the steering wheel, there is a delay in the time the wheel turns and the tire contact patch turns. The higher the sidewall, the more delay there is. This delay affects what is felt in turn-in. Also, more sidewall changes how the tire heats up. More sidewall means more flex and more flex means more heat as the sidewall flexes.
Instead of a LSD, I would put that money towards the best dampers and springs you can buy along with a driver's school. Nothing improved my lap times faster than a trip to Team O'Neil. Nothing made me slower than throwing different parts on the car in between events.