Never played in Portugal, but I bet a lot of South and Central Americans should be easy to convince. Scout it asap. Also look at some Scandinavians, they usually have good adaptability, so they'll be playing well fast.
Had a look at the SCP squad in my Brøndby game, it seems you need a GK and a left mid/winger. Look for young guys who can play instantly. Erick Delgado (22, Peruvian) might be a good GK, and Tobias Hysén (23, Swedish) may be good on the wing.
Other than that, look where you lack depth, and add some backup where needed. Also look for some talented youths, preferably Portuguese lads.
Expensive? Look for how much their release cluase are. Sometimes it is lower than their valued price. For example I just got a guy for 100k and his vauled pirce was 500k....pretty good deal. In your search screen customize the abilties to what you want. For example If I am looking for a striker, I will customize it so that his heading, finishing, off the ball, dribbling, compousre, and concentration are all 15 at least. Than I see how many players come up with that stat and look for the ceaper ones that are good enough for my team.
tanks i like to think i am a good manager as i once got oldham relegated to league 2 ... but then got them to the premiership in 4 seasons.
learn from your mistakes iv only managed them sporting and birmingham so im not all that experienced