HCG is not necessary but a lot of guys enjoy it on HRT because it can augment mood and libido. It will preserve testicular volume and keep the LH pathway going as well. If the dose is low and frequent, estrogen issues are normally not a concern. 500 IU a week in divided doses is a good starting point.
200mg per week is not a smart starting dose, you want to start low and go slow with HRT. 100mg in bi-weekly injections is a good starting point and depending on how you feel and your labs adjustments in dose can be made. AI is not necessary unless you are symptomatic and have elevated numbers. I personally think the less medications you have to work with, the better, but I would absolutely advocate for HCG.