I'm currently playing as Fiorentina and Frey has been outstanding for me, so I would recommend activating his foreign club release clause of 12 million.
For LB check Davide Santon (Inter), Alex Sandro (Santos), Michal Kadlec (Leverkusen), José Angél (Sporting), Gabriel Silva (Palmeiras), Cheick M'Bengué (Toulouse FC), Domenico Criscito (Genoa), Jordi Alba (Valencia), Ignacia Monreal (Osasuna) or Reto Ziegler (Sampdoria).
For a cheap, young striker, go for Vaclav Kadlec; you'd have no problem signing him as Liverpool is one of his favourite clubs. He needs time though. Be fast, too, as he's always wanted at the beginning of he game.
If you want some instant goal scoring ability, go for Vágner Love (CSKA Moscow), Seydou Doumbia (either Young Boys or CSKA Moscow; not sure)