Yeah I would do chain and tome.
I'm not a fan of Pact of the Blade. Wifes playing one. It is invocation heavy and you're basically a bad Paladin. Tomes great for utility especially early on.
Class kinda seems to top out at level 11/12 as well. And its front loaded.
Im not even convinced Pact of Anything is the best approach. pact of all/lots the origin feats for example is very good. Think I would double down on control and eh on striker now.
I think agonizing Truestrike works better than Pact of Blade for a bladelock at most levels. The flat +3/4/5 and extra cantrip damage dice keep up fairly close with extra attack, you get scaling at 5, 11 and 17 and you only need one invocation for it.