short term and long term rentals on Gib.

Hi there.
My wife and I live on the Costa Brava, Spain.  We are now retired and intend to make a permanent move to Gibraltar as soon as we have sold our house here.

Our goal is to find a long-term rental rather than buy an apartment, so that we can live off the money from the sale of our house to supplement our U.K. pension.

The only way to be on hand to view properties would be to rent short-term locally, so that we can be on hand to view long term apartments. 

Would you advise the initial short-term rental to be on Gib or on the Spanish side? (We have a car.)  If in Spain, where?..La Linea doesn't look very inspiring!   We'd like it to be reasonably comfortable and furnished but not much more than around 1000-1200 Euros / 1,000 Pounds per month.

Thanks in advance for your help and advice, and also for any guide on the best (maybe online) agents to use.