What's your wage budget and transfer budget? What's your average player salary and how much do you have left to spend? These are essentials to know before recommendation can be made. Without knowing your budget, I'd say your best bet is to loan someone with 3-4 star rating for your league level. Make sure you have good scouts and you should be able to find some bargains. Download a wonderkid under 21 shortlist and have your scouts give you a report on all of them. I know that Neal Maupay (France) is a great longterm buy for your side if you can afford him but you might not be able to with your budget constraints.