It is hard to know who you should get, as I don't know how much resources you have. Lots of rumours you could spend a fortune, but until that happens - that's all it is rumours. Not saying you won't, but who you should target should will changes depending on your budget.
However regardless of the budget, I feel a GK needs to arrive. Howard was letting you down last season and I don't think the two keepers you have now are good enough, despite the odd game where they do well. They don't look solid enough and make too many costly errors.
Your wide players all seem very disappointing to me. Lennon, Deulofeu, Mirallas - none of these look big goal threats or even suppliers to me. Bolasie is a big loss in that regard as although he was hit and miss - at least he had those hits and would supply Lukaku at times.
Lukaku is a striker that relies on service and to be fair to him when he gets that service he is one of the best finishers in the league. But he is feeding off scraps a lot of the time and you need to find some creativity and someone to feed him.
Lukaku really needs a strike partner alongside him. Or two inside forwards in a 4-3-3. You don't appear to have either. I also don't see how Barkley and Lukaku really work together. I think the club might be better off making a decision on these two and deciding which one you want to keep (if either of them) and build a team round that player. I feel it might be hard to build a team round both of them as they don't see to compliment each other from what I can see.
Koeman needs to decide on the formation he wants, the brand of football he wants and then he needs to be ruthless in getting rid of the players - even if they are stars like Lukaku. No point in keeping Lukaku if Koeman wants to play a high tempo, pressing game - as he's not that type of striker. Equally no point in keeping Barkley if the plan is to play 4-4-2, buying a partner to compliment Lukaku and then it is hard to see how Barkley fits in a 4-4-2.
Some of your best players don't compliment each other from what I can see. As a LFC fan we had that when Coutinho was meant to try and supply Lambert. Both wanted to play the game different ways. Lambert wanted crosses, Coutinho wanted movement so he could pass the ball to feet. It didn't work. I don't think your attack currently works. It looks best when Valencia is in the team as he gets closer to Lukaku, to give him support. He also does the pressing that Lukaku doesn't do, this creates space for Lukaku to exploit. No surprise to me you have scored you goals in recent weeks when Valencia is on the field. He's not the best players in the world, far from it. But he does help bring the best out of Lukaku - that is something I don't think Barkley does & vice versa, Lukaku doesn't do it for Barkley.
Sometimes teams can sell a star and be better off. Man Utd did it when they sold RVN, their top scorer the season before despite them not winning the league. They bought an uninspiring Carrick. They already had enough goals in the team with Rooney, Ronaldo etc. What they needed was control in midfield and Carrick did that. They then won the league and Champs League in the next two years.
Arsenal did it when they sold Henry to Barca. They lost their best player, but their whole attack was based around him, they were not really a team - he was their attack and they were coming 4th in the league. They sold him, bought Eduardo - others stepped up and they nearly won the league that season. I think they would have had Eduardo not have received that awful injury.
Koeman needs to be ruthless and make tough decisions so you are a better team overall. Personally I think you should cash in on Lukaku and buy the players to suit a more high, energy pressing game. I feel if you did that then Barkley might come alive again. Barkley's stock is currently low, but I think he has proven what a special player he can be in the right set up and when on form.
If he persists with Lukaku and Barkley, tries to shoe horn players in around them, like a Depay - then I fear that could be the worst thing he could be doing. As he is persisting with what doesn't work. Sometimes you have to break a few eggs, for that omelette.
