We're out in Tarifa at the moment and we looked for ages for accommodation and generally its expensive and what you get is not always that good but we've had some great apartments from Tarifa Direct (http://tarifadirect.com/
), speak to Frank he's always really helpful
Realistically you need quite a wide range of kites definitely 12m -> 7m, smaller if you want to kite in Tarifa when the Levante wind really blows (but best to escape to some of the spots a short drive away where is a lot lighter!)
In Levante winds always head up to the dunes end of the bay and kite at any of beaches between Valdevaqueros and Punta La Paloma. Just beware that it will get really busy as everyone is squeezed in to this kilometre of beach, so get down early if its windy as lot of people won't turn up until 3 when there hangover start to wear off!
In Poniente winds, you have a lot more flexibility as you can kite pretty much anywhere along the 8km of beach. If its lighter then you will probably get better conditions up towards Dos Mares Hotel or the dunes area otherwise its all good and just look for where its less busy. Definitely recommend a downwinder back to town at the end of your session, always fun!!
Whatever happens you'll have a great time here just be prepared for lots of kiting, eating lots of amazing tapas and if you up for it, some great parties - just prepared no one starts drinking until midnight and the clubs don't open until 2/3am!
All the best