Auction tank recommendations

I took a hiatus from playing blitz and have come back because I have around 13k gold and the auctions sounds pretty sweet. That being said, what should I look forward too? What tank is a must have for you guys? I had a chance to get the anni but I passed since I’d rather but a tier 9 or 10. I already have the obj 752, 907, E6, Concept 1B, snd 121, big fan of mediums. I’ve been eyeballing the Char 4, is it strong right now?