Estate Agents get a bad press, often deservedly. Most of them are nice people but they get misled by the need to make a sale whilst the buyers who are often seduced by 'A Place in the Sun' want the agents help to firstly decide which area they want to buy in. Which is frustrating for all and leads to agents making mistakes and clients having a bad time.
The main business of Remax is selling franchises to sell property - not selling property. Portuguese run companies don't understand the requirements of UK buyers and frankly the whole business seems a bit of a mess.
Why not choose where you want to buy, then follow with a look at Meravista which has thousands of properties on it.
Decide the location, get a feeling for budget and develop a wish list - then approach a well managed agency preferably with UK RICS level of quality staff and ask them which homes in their inventory fit your wish list.