Check out
www.Airdesertpacific.com. They offer time building in an archer for $28. If you can find it cheaper i'll be amazed.
Its in L.A so the weather is good. in 10 weeks youll get the extra 100 hours you need no problem.
Im doing an instrument rating with them at the moment and planning to convert to a JAA IR later. Its the cheapest way of getting the JAA IR that ive found. You save about 5000GBP.
There is some ground school involved but thats all included in the package. You need 50 hours X-country, 40 hours under the hood, and 15 hours dual instruction prior to the check ride. Conversion to JAA i believe involves 15 hours in a twin plus all tests.
I Hope this helps.