I'm not sure there is much more of an attacking option than Moses. It seems strange to call him defensively weak (which is true) but also call for someone more attack minded. I do agree his crossing is frequently painful though.
I understand the plan is that Christensen is coming home next year anyway, so I was kind of assuming he'd be stepping in. With Zouma back now also, CB seems pretty much sorted and I'd actually be a bit worried if we looked to buy in someone new. Christensen looks like the real deal, and I'd hate him to leave because of a perceived lack of oppoortunity. Christensen-Luiz-Zouma would be incredible, although then it'd mean pushing Azpi out to wingback and he's not the most attack minded. It'll be interesting to see what Conte decides.
I'd take Sanchez in a heartbeat given the opportunity, and I agree about the positions. Not sure about Romelu, I was a big fan and his goal rate is impressive, but I suspect he would annoy the hell out of us frequently and I certainly wouldn't drop Costa for him.