Top 3 needs are LG, FS,and RG
greg van roten is a good budget RG and from free safety you could do 97 Ed Reed he sells for about 160k
Another player you could get is 96 Bruce Matthews. He goes for under 170k on every platform, and he is better than Van Roten although he is a different position (LG instead of RG). Roten would be good as well though. You could even go cheaper, like with 95 Ed Engram or 95 Elijah Wilkinson, who both go for 100k or less.
At safety, I personally would get 96 UL Sean Taylor. Although obviously it is a different card, his 92 Legends card was incredible for me this year. You could buy him for just over 100k at most. You could also get Kevin Byard. He is more expensive (135k at most) but he might be the better player for you. I would still go Taylor though. He has equal speed and zone coverage, but has 15 more hit power and more acceleration and tackle. His block shedding is 27 higher, and he is also taller by 3 inches.)
Remember that these are just suggestions. I hope this helped :)