EK/AT is a viable build.

The idea is too take the classes in 3's for spell slot purposes, but you don't have too.. because there are points in the build where you may want other features. You may only go 7-8 levels of EK, you may only go 7-8 for AT

Either way, war caster is a must if you plan on using a real shield. I prefer S&B for this build with a rapier.

If you go strength based, just have a 14 in dexterity and save up money for breastplate, but in the mean time... mage armor will suffice as will scale mail (disadvantage on stealth though)

And with a 13 in intelligence or more... you can occasionally grab a level of wizard here and there... I recommend evocation for sculpt spell

And though you may not get to launch a fireball, you'll have the higher spell slots to upcast lower level spells