You can't go wrong with a TheMightyHobie18. Fast and fun but still quite forgiving and not as flighty as the F16/F18 (more margin for error before you go swimming). They are also very strong and take a lot of abuse.

If you want more performance the F18 is a great choice. As far as F18 manufacturer - choose whatever is being sailed most in your area. I am onto my 2nd Tiger and have found them to be an excellent all round boat. They can be a handful but are also very forgiving if you back off and take it easy in a blow. Any spinnaker boat will cost more to run than a non spi boat if you are racing seriously.

Tiger Mike