I had mentioned this possible solution in the Cyprus Problem forum some time ago. I still think that it is the best chance for a functioning state the size and population of Cyprus.
1. A new constitution to be drawn up to specifically state no federal government setup. A totally unitary state. Electoral boundaries made up on basis of overall population dispersal.
2. Bicarmal legislature would govern Cyprus. Lower house (assembly) elected by popular ballot. Upper House (senate) appointed on basis of the principal communities in Cyprus: Greek, Turkish, Armenian, Marionite, and Others. Each community gets equal number of senators. Senatorial appointments made by the political parties with elected representation.
3. Bills passed by the lower house require endorsement of the Senate by 2/3rds majority before being forwarded to the President to be signed into law.
4. President and Vice President elected on seperate ballot without ethnic requirement beside sole citizenship of Republic of Cyprus (no dual citizenship of any other country allowed for holders of these two offices).
5. No political parties permitted espousing the philosophies of taksim or enosis. No political parties that have membership bias based on ethnic background or origin to be permitted. Independent candidates to sign statement indicating agreement not to support either taksim or enosis before being allowed to run for office.
6. Removal of the official status of the Greek and Turkish languages in government. Only English to be permitted. Governmen employees must have command of the English language.
7. The Treaty of Guarantee to be removed and replaced with a Treaty of Sovereignty to be enforced by the European Union. Only EU troops to be deployed on the island.
8. The Sovereign Base Areas to be ceded to the Cyprus Republic.
9. Property issues dating back to before December 1963 to be properly addressed. Settlers brought in from other countries to be repatriated.
10. The National Anthem of Cyprus to be replaced with a neutral song, reflecting the sovereign status of the island.
11. For initial period, Law enforcement to be done by EU police force to ensure total non-bias. Cypriot law enforcement and armed forces not permitted for initial period.