Another vote for Eloy. I live in the UK and have jumped in California, Arizona and Florida and based on your requirements my opinion is Eloy is your best bet. I've made 9 trips there and it is by far my preference if you want to jump hard. You can get a direct flight to Phoenix from Heathrow, there is a friendly affordable shuttle service (Tammy Arrowsmith) - for a small surchare she will stop at Walmart so you can get your supplies en-route to the DZ (bunkhouse has fridge/freezers and a microwave).
And a small tip, if you don't have any go get some earplugs at the tunnel because you could have someone like me sleepin in a bunk near you...
Will
PS you will have a great time at most warmer winter US dropzones, don't let us bias you, but once you've decided on Eloy PM me if you want some money saving tips on flights etc.